Properties of the Number 21157

Twenty-One Thousand One Hundred Fifty-Seven

Basics

Value: 21156 → 21157 → 21158

Parity: odd

Prime: Yes

Previous Prime: 21149

Next Prime: 21163

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 21157

Divisors: 1, 21157

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101001010100101

Octal: 51245

Duodecimal: 102B1

Hexadecimal: 52a5

Square: 447618649

Square Root: 145.45446022724775

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

Primes that are palindromic in base 2 (but written here in base 10). A16041

Expansion of g.f. A(x) satisfying A(x) = A( x²*(1+x)² ) / x. A369552

Primes p such that the decimal digits of p² can be partitioned into two or more nonzero squares. A48646

a(n) is the number whose binary expansion is A153498(n). A153497

Consider two consecutive primes {p,q} such that P=2p+q and Q=2q+p are both prime. The sequence gives primes Q. A248483

Numbers k such that (29·10^k-1 + 7)/9 is a depression prime. A82705

Take A163498(n) written in binary, insert a 0 before every 1. a(n) is the decimal equivalent of the result. A163499

Prime numbers whose base-2 representation is a "nested" palindrome. A373581

Numbers whose base-2 representation is a "nested" palindrome. A373941

Numbers whose base-2 representation has exactly 13 runs. A43580