Properties of the Number 20475

Twenty Thousand Four Hundred Seventy-Five

Basics

Value: 20474 → 20475 → 20476

Parity: odd

Prime: No

Previous Prime: 20443

Next Prime: 20477

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 ² × 7 × 13

Divisors: 1, 3, 5, 7, 9, 13, 15, 21, 25, 35

Polygonal

Triangular: No

Square: No

Pentagonal: Yes

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111111111011

Octal: 47773

Duodecimal: BA23

Hexadecimal: 4ffb

Square: 419225625

Square Root: 143.09088021254183

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

Binomial coefficient binomial(n,4) = n*(n-1)*(n-2)*(n-3)/24. A332

a(n) = σ(n) * A003961(n), where A003961 shifts the prime factorization of n one step towards larger primes, and σ is the sum of the divisors of n. A341529

Sum of all partitions of n into distinct parts. A66189

Number of regions in regular n-gon which are quadrilaterals (4-gons) when all its diagonals are drawn. A67151

Consider the base-8 Kaprekar map n->K(n) defined in A165090. Sequence gives numbers belonging to cycles, including fixed points. A165095

Table by antidiagonals of number of ways of choosing k items from n·k. A60539

Consider the base-8 Kaprekar map n->K(n) defined in A165090. Sequence gives numbers belonging to cycles of length greater than 1. A165097

a(n) = binomial(2ⁿ + 3·n, n). A132688

Binomial coefficient C(7n,n). A4368

Triangle, read by rows, where T(n,k) = C(n*(n-1)/2-k*(k-1)/2+n-k+2, n-k). A107870