Properties of the Number 21425

Twenty-One Thousand Four Hundred Twenty-Five

Basics

Value: 21424 → 21425 → 21426

Parity: odd

Prime: No

Previous Prime: 21419

Next Prime: 21433

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 ² × 857

Divisors: 1, 5, 25, 857, 4285, 21425

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001110110001

Octal: 51661

Duodecimal: 10495

Hexadecimal: 53b1

Square: 459030625

Square Root: 146.37281168304446

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

Expansion of sum ( qⁿ / product( 1-q^k, k=1..3·n), n=0..inf ). A35295

A self-"read and extend" sequence built following the rules visible in the Comments section (a kind of Collatz-by-digits sequence). A316764

Number of mutual-visibility sets in the n-prism graph. A389184

Number of dominating sets in the n-double cone graph. A365581

Expansion of (-1+1/(1-5·x)⁵)/(25·x); related to A036071. A36083

Number of (n+1)X(5+1) 0..1 arrays with no element having a strict majority of its horizontal and antidiagonal neighbors equal to one. A231994

Decimal expansion of 1/421. A21425