Properties of the Number 2640

Two Thousand Six Hundred Forty

Basics

Value: 2639 → 2640 → 2641

Parity: even

Prime: No

Previous Prime: 2633

Next Prime: 2647

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 ⁴ × 3 × 5 × 11

Divisors: 1, 2, 3, 4, 5, 6, 8, 10, 11, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 101001010000

Octal: 5120

Duodecimal: 1640

Hexadecimal: a50

Square: 6969600

Square Root: 51.38093031466052

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

Octagonal numbers: n*(3·n-2). Also called star numbers. A567

Sum of all parts of all partitions of n. A66186

a(n) = 5·a(n-1) - a(n-2) for n > 1, a(0) = 0, a(1) = 1. A4254

Sums of twin prime pairs. A54735

Number of partitions of n into parts of 3 kinds. A716

a(n) = binomial(n+5,5)*(n+3)/3. A40977

7-fold factorials: a(n) = ∏_k=0..n-1 (7·k+1). A45754

Numbers k such that σ(k) > 3·k. A68403

Expansion of η(q)⁵ * η(q³) * η(q⁶)⁴ / η(q²)⁴ in powers of q. A214262

Number of integer partitions of n such that the greatest part is the unique mode. A362612