9000 (number)

**9000** (**nine thousand**) is the natural number after 8999 and before 9001.

## Selected numbers: 9001–9999
### 9001 to 9099
* **9001** – sexy prime with 9007
* **9007** – sexy prime with 9001
* **9009** – centered cube number
* **9025** = 952, centered octagonal number
* **9029** – Sophie Germain prime
* **9041** – super-prime
* **9045** – triangular number
* **9059** – Sophie Germain prime
* **9072** – decagonal number
* **9077** – Markov number
* **9091** – unique prime

### 9100 to 9199
* **9103** – super-prime
* **9126** – pentagonal pyramidal number
* **9139** – tetrahedral number
* **9175** – smallest (provable) generalized Sierpiński number in base 10:  is always divisible by one of the prime numbers {{math|{7, 11, 13, 73}}}.
* **9180** – triangular number

### 9200 to 9299
* **9216** = 962
* **9221** – Sophie Germain prime
* **9224** – octahedral number
* **9241** – cuban prime of the form *x* = *y* + 1
* **9261** = 213, largest 4 digit perfect cube
* **9272** – weird number
* **9283** – centered heptagonal number
* **9293** – Sophie Germain prime, super-prime

### 9300 to 9399
* **9316** – triangular number
* **9319** – super-prime
* **9334** – nonagonal number
* **9349** – Lucas prime, Fibonacci number
* **9371** – Sophie Germain prime
* **9376** – 1-automorphic number
* **9397** – balanced prime

### 9400 to 9499
* **9403** – super-prime
* **9409** = 972, centered octagonal number
* **9419** – Sophie Germain prime
* **9439** – completes the twelfth prime quadruplet set
* **9453** – triangular number
* **9455** – square pyramidal number
* **9457** – decagonal number
* **9461** – super-prime, twin prime
* **9467** – safe prime
* **9473** – Sophie Germain prime, balanced prime, Proth prime
* **9474** – Narcissistic number in base 10
* **9479** – Sophie Germain prime
* **9496** – Telephone/involution number

### 9500 to 9599
* **9511** - prime number 
* **9521** - prime number 
* **9533** - prime number
* **9539** – Sophie Germain prime, super-prime
* **9551** – first prime followed by as many as 35 consecutive composite numbers
* **9587** – safe prime, follows 35 consecutive composite numbers
* **9591** – triangular number
* **9592** - amount of prime numbers under 100,000

### 9600 to 9699
* **9601** – Proth prime
* **9604** = 982
* **9619** – super-prime
* **9629** – Sophie Germain prime
* **9647** – centered heptagonal number
* **9661** – super-prime, sum of nine consecutive primes (1049 + 1051 + 1061 + 1063 + 1069 + 1087 + 1091 + 1093 + 1097)
* **9689** – Sophie Germain prime
* **9699** – nonagonal number

### 9700 to 9799
* **9721** – prime of the form 2p-1
* **9730** – triangular number
* **9739** – super-prime
* **9743** – safe prime
* **9791** – Sophie Germain prime

### 9800 to 9899
* **9800** – member of a Ruth-Aaron pair (first definition) with 9801
* **9801** = 992, the largest 4 digit perfect square, centered octagonal number, square pentagonal number, member of a Ruth-Aaron pair (first definition) with 9800
* **9833** – super-prime
* **9839** – safe prime
* **9850** – decagonal number
* **9855** – magic constant of *n* × *n* normal magic square and n-Queens Problem for *n* = 27.
* **9857** – Proth prime
* **9859** – super-prime
* **9870** – triangular number
* **9871** – balanced prime
* **9880** – tetrahedral number
* **9887** – safe prime

### 9900 to 9999
* **9901** – unique prime, sum of seven  primes (1381 + 1399 + 1409 + 1423 + 1427 + 1429 + 1433)
* **9905** – number of compositions of 16 whose run-lengths are either weakly increasing or weakly decreasing
* **9923** – super-prime, probably smallest certainly executable prime number on x86 MS-DOS
* **9949** – sum of nine consecutive primes (1087 + 1091 + 1093 + 1097 + 1103 + 1109 + 1117 + 1123 + 1129)
* **9973** – super-prime
* **9999** – Kaprekar number, repdigit

### Prime numbers
There are 112 prime numbers between 9000 and 10000:
:9001, 9007, 9011, 9013, 9029, 9041, 9043, 9049, 9059, 9067, 9091, 9103, 9109, 9127, 9133, 9137, 9151, 9157, 9161, 9173, 9181, 9187, 9199, 9203, 9209, 9221, 9227, 9239, 9241, 9257, 9277, 9281, 9283, 9293, 9311, 9319, 9323, 9337, 9341, 9343, 9349, 9371, 9377, 9391, 9397, 9403, 9413, 9419, 9421, 9431, 9433, 9437, 9439, 9461, 9463, 9467, 9473, 9479, 9491, 9497, 9511, 9521, 9533, 9539, 9547, 9551, 9587, 9601, 9613, 9619, 9623, 9629, 9631, 9643, 9649, 9661, 9677, 9679, 9689, 9697, 9719, 9721, 9733, 9739, 9743, 9749, 9767, 9769, 9781, 9787, 9791, 9803, 9811, 9817, 9829, 9833, 9839, 9851, 9857, 9859, 9871, 9883, 9887, 9901, 9907, 9923, 9929, 9931, 9941, 9949, 9967, 9973

## References