Properties of the Number 21899

Twenty-One Thousand Eight Hundred Ninety-Nine

Basics

Value: 21898 → 21899 → 21900

Parity: odd

Prime: No

Previous Prime: 21893

Next Prime: 21911

Digit Sum: 29

Digital Root: 2

Palindrome: No

Factorization: 61 × 359

Divisors: 1, 61, 359, 21899

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010110001011

Octal: 52613

Duodecimal: 1080B

Hexadecimal: 558b

Square: 479566201

Square Root: 147.98310714402507

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(1)=3; for n > 1, a(n) = 1 + a(n-1) + gcd( a(n-1)*(a(n-1)+2), A073829(a(n-1)) ). A167053

a(n) = A007678(2·n)/(2·n). A341734

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 19 ones. A31787

Number of (n+1) X (n+1) -4..4 symmetric matrices with every 2 X 2 subblock having sum zero and one or two distinct values. A211490

Number of free highly irregular trees with n nodes. A259864

Fixed points in A375564. A376584

Numerator of the sum of the reciprocals of all square divisors of all positive integers <= n. A384817

Engel expansion of the twin primes constant ~ .660161815846869573927812110014555778432623360284733413319448. A96189

Number of nX4 0..1 arrays with every element unequal to 2, 3, 4, 5, 6, 7 or 8 king-move adjacent elements, with upper left element zero. A317461

Decimal expansion of 1/895. A21899