Properties of the Number 20405

Twenty Thousand Four Hundred Five

Basics

Value: 20404 → 20405 → 20406

Parity: odd

Prime: No

Previous Prime: 20399

Next Prime: 20407

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 5 × 7 × 11 × 53

Divisors: 1, 5, 7, 11, 35, 53, 55, 77, 265, 371

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111110110101

Octal: 47665

Duodecimal: B985

Hexadecimal: 4fb5

Square: 416364025

Square Root: 142.84607099952032

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

Number of partitions of n such that (number of distinct parts) = maximal multiplicity of the parts. A239964

Numbers k such that k and k+1 have 4 distinct prime factors. A140078

Coefficients in the expansion of C/B², in Watson's notation of page 106. A160461

Moebius transform of binomial(n+3, 4). A117109

Numbers k such that k and k+1 each have at least 4 distinct prime factors. A321504

Numbers k such that k and k+1 are the product of exactly four distinct primes. A318896

A diagonal of A008296. A59302

Consider recurrence b(0) = (2n+1)/2, b(n) = b(0)*floor(b(n-1)); sequence gives first integer reached. A87675

Numbers with digit sum 11 that are multiples of 11. A283742

Numbers k such that k + A067666(k) is a square. A386257