7000 (number)

**7000** (**seven thousand**) is a natural number. It is between 6999 and 7001.

## Important numbers 7001–7999
### 7001 to 7099
* **7021** – triangular number
* **7043** – Sophie Germain prime
* **7056** = 842
* **7057** – the cuban prime of *x* = *y* + 1. It is also a super-prime
* **7073** – Leyland number
* **7079** – a Sophie Germain prime and a safe prime

### 7100 to 7199
* **7103** – a Sophie Germain prime and a sexy prime with 7109
* **7106** – an octahedral number
* **7109** – a super-prime sexy prime with 7103
* **7121** – a Sophie Germain prime
* **7140** – a triangular number, and a pronic number. Since  = 3570, 3570 is also a triangular number and tetrahedral number
* **7151** – Sophie Germain prime
* **7155** – the number of 19-bead necklaces (turning over is allowed) where complements are the same
* **7187** – safe prime
* **7192** – weird number
* **7193** – Sophie Germain prime, super-prime

### 7200 to 7299
* **7200** – pentagonal pyramidal number
* **7211** – Sophie Germain prime
* **7225** = 852, centered octagonal number
* **7230** = 362 + 372 + 382 + 392 + 402 = 412 + 422 + 432 + 442
* **7246** – centered heptagonal number
* **7247** – safe prime
* **7260** – triangular number
* **7267** – decagonal number
* **7272** – Kaprekar number
* **7283** – super-prime
* **7291** – nonagonal number

### 7300 to 7399
* **7316** – the number of 18-bead binary necklaces with beads of 2 colors where colors can be swapped, but turning over is not allowed
* **7338** – Fine number
* **7349** – Sophie Germain prime
* **7351** – super-prime, cuban prime of the form *x* = *y* + 1
* **7396** = 862

### 7400 to 7499
* **7417** – super-prime
* **7433** – Sophie Germain prime
* **7471** – centered cube number
* **7481** – super-prime, cousin prime

### 7500 to 7599
* **7503** – triangular number
* **7523** – balanced prime, safe prime, super-prime
* **7537** – prime of the form 2p-1
* **7541** – Sophie Germain prime
* **7559** – safe prime
* **7560** – highly composite number
* **7561** – Markov prime
* **7568** – centered heptagonal number
* **7569** = 872, centered octagonal number
* **7714** – square pyramidal number
* **7727** – safe prime
* **7739** – member of the Padovan sequence
* **7741** = number of trees with 15 unlabeled nodes
* **7744** = 882, square palindrome not ending in 0
* **7750** – triangular number
* **7753** – super-prime
* **7770** – tetrahedral number

### 7800 to 7899
* **7810** – ISO/IEC 7810 is the ISO's standard for physical characteristics of identification cards
* **7821** – n=6 value of \sum_{k=1}^{n}n^{floor(\frac{n}{k})-1}
* **7823** – Sophie Germain prime, safe prime, balanced prime
* **7825** – magic constant of *n* × *n* normal magic square and n-Queens Problem for *n* = 25. It is also the first counterexample in the Boolean Pythagorean triples problem.
* **7841** – Sophie Germain prime, balanced prime, super-prime
* **7875** – triangular number
* **7883** – Sophie Germain prime, super-prime
* **7897** – centered heptagonal number

### 7900 to 7999
* **7901** – Sophie Germain prime
* **7909** – Keith number
* **7920** – the order of the Mathieu group M11, the smallest sporadic simple group
* **7921** = 892, centered octagonal number
* **7944** – nonagonal number
* **7957** – super-Poulet number
* **7965** – decagonal number
:7001, 7013, 7019, 7027, 7039, 7043, 7057, 7069, 7079, 7103, 7109, 7121, 7127, 7129, 7151, 7159, 7177, 7187, 7193, 7207, 7211, 7213, 7219, 7229, 7237, 7243, 7247, 7253, 7283, 7297, 7307, 7309, 7321, 7331, 7333, 7349, 7351, 7369, 7393, 7411, 7417, 7433, 7451, 7457, 7459, 7477, 7481, 7487, 7489, 7499, 7507, 7517, 7523, 7529, 7537, 7541, 7547, 7549, 7559, 7561, 7573, 7577, 7583, 7589, 7591, 7603, 7607, 7621, 7639, 7643, 7649, 7669, 7673, 7681, 7687, 7691, 7699, 7703, 7717, 7723, 7727, 7741, 7753, 7757, 7759, 7789, 7793, 7817, 7823, 7829, 7841, 7853, 7867, 7873, 7877, 7879, 7883, 7901, 7907, 7919, 7927, 7933, 7937, 7949, 7951, 7963, 7993

## References