Properties of the Number 21880

Twenty-One Thousand Eight Hundred Eighty

Basics

Value: 21879 → 21880 → 21881

Parity: even

Prime: No

Previous Prime: 21871

Next Prime: 21881

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ³ × 5 × 547

Divisors: 1, 2, 4, 5, 8, 10, 20, 40, 547, 1094

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010101111000

Octal: 52570

Duodecimal: 107B4

Hexadecimal: 5578

Square: 478734400

Square Root: 147.91889669680478

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

a(n) is the starting position of the first occurrence of a string of exactly n 6's in the decimal expansion of π. A96760

30-gonal numbers: a(n) = n*(14·n-13). A254474

Intrinsic 10-palindromes: n is an intrinsic k-palindrome if it is a k-digit palindrome in some base. A60947

Number of partitions p of n such that (1/5)*max(p) is a part of p. A363068

a(n) = -a(n-1) + a(n-2) - F(-n) + 1, a(0) = 1, a(1) = -1, where F() = Fibonacci numbers A000045. A175722

Right edge of the triangle in A033291. A192736

Analog of Motzkin sums for Coxeter type D. A290380

Glaisher's function V(n). A2611

a(n) is the starting position of the first occurrence of a string of at least n consecutive digits '6' in the decimal expansion of π. A50285

Starting positions of strings of four 6's in the decimal expansion of π. A83626