Properties of the Number 21975

Twenty-One Thousand Nine Hundred Seventy-Five

Basics

Value: 21974 → 21975 → 21976

Parity: odd

Prime: No

Previous Prime: 21961

Next Prime: 21977

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 ² × 293

Divisors: 1, 3, 5, 15, 25, 75, 293, 879, 1465, 4395

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010111010111

Octal: 52727

Duodecimal: 10873

Hexadecimal: 55d7

Square: 482900625

Square Root: 148.23967080373595

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 composites removed in each step of the Sieve of Eratosthenes for 10⁷. A227155

Numbers k such that k divides the sum of digits in factorial base of all numbers from 1 to k. A333702

Number of different positions in which a square with side length k, 1 <= k <= n - floor(n/3), can be placed within a bi-symmetric triangle of 1 X 1 squares of height n. A241526

a(n) = number of triangles with integer sides i <= j <= k with radius of circumcircle <= n. A331229

Floor[ concatenation of n+4, n+3, n+2, n+1 and n divided by 5]. A75006

Number of geodetic graphs with n unlabeled vertices. A337179

Table with g.f. [1-x·n-sqrt(x²*n²-2·n*x+1+4·x²-4·x)]/(2·x). A128888

Decimal expansion of 1/971. A21975