Properties of the Number 51681

Fifty-One Thousand Six Hundred Eighty-One

Basics

Value: 51680 → 51681 → 51682

Parity: odd

Prime: No

Previous Prime: 51679

Next Prime: 51683

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 7 × 23 × 107

Divisors: 1, 3, 7, 21, 23, 69, 107, 161, 321, 483

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1100100111100001

Octal: 144741

Duodecimal: 25AA9

Hexadecimal: c9e1

Square: 2670925761

Square Root: 227.33455522643274

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

a(n) = n·Fibonacci(n-2) + ((-1)ⁿ + 1)/2. A323812

Triangular numbers (A000217) that are the sum of seven consecutive triangular numbers. A257711

Triangular numbers n such that σ(n) is a square number. A256151

Triangular numbers t which are average of two consecutive primes p and p+4. A129752

Triangular numbers t such that t+10 is a prime. A129755

The function W_n(6) (see Borwein et al. reference for definition). A169711

Triangular numbers with sum of digits = 21. A68131

Triangular numbers in which the k-th significant digit either divides k or is a multiple of k. A69559

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) - b(n-2) + 1, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4. A294422

Triangular numbers for which the sum of the digits is an octagonal number. A117523