Properties of the Number 21457

Twenty-One Thousand Four Hundred Fifty-Seven

Basics

Value: 21456 → 21457 → 21458

Parity: odd

Prime: No

Previous Prime: 21433

Next Prime: 21467

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 43 × 499

Divisors: 1, 43, 499, 21457

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001111010001

Octal: 51721

Duodecimal: 10501

Hexadecimal: 53d1

Square: 460402849

Square Root: 146.482080815368

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

Composite and every divisor (except 1) contains the digit 4. A62670

T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 4 6 or 7. A252105

MM-numbers of crossing set partitions. A324324

a(n) = (1/2)*(n³ - 6·n² + 13·n - 6). A158498

Numbers k such that k¹⁰ == 1 (mod 11⁴). A56094

Expansion of 1/sqrt((1 - x³ - x⁴)² - 4·x⁷). A376721

a(n) = n⁴ + 5·n² + 1. A82113

Form a conjugate partition of row with 1+1+1 in first row. all other rows are the union of their parents. a(n) = number of types of piles in the n-th row. A64480

Number of 3Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4. A241308

Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 4 6 or 7. A252098