Properties of the Number 2157

Two Thousand One Hundred Fifty-Seven

Basics

Value: 2156 → 2157 → 2158

Parity: odd

Prime: No

Previous Prime: 2153

Next Prime: 2161

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 719

Divisors: 1, 3, 719, 2157

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 100001101101

Octal: 4155

Duodecimal: 12B9

Hexadecimal: 86d

Square: 4652649

Square Root: 46.44351407893249

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Numbers k such that 8·10^k - 49 is prime. A271269

Crystal ball sequence for hexagonal close-packing. A7202

Coordination sequence for 3D uniform tiling formed by stacking parallel layers of the 3.12.12 2D tiling (cf. A250122). A299257

Number of integer partitions of n such that the parts have the same mean as the multiplicities. A360068

Sum of first n semiprimes. A62198

a(n) = p(1)p(n) + p(2)p(n-1) + ... + p(k)p(n+1-k), where k = [ (n+1)/2 ], p = A000040 = the primes. A24697

Number of primes in the interval [prime(n), prime(n)²]. A54272

Add/multiply sequence, see example. A93361

Toothpick sequence on the hexagonal net starting from a node. A182632

Expansion of 1 / ((1-x)²*(1-x²)*(1-x³)*(1-x⁴)). A2621