Properties of the Number 21127

Twenty-One Thousand One Hundred Twenty-Seven

Basics

Value: 21126 → 21127 → 21128

Parity: odd

Prime: No

Previous Prime: 21121

Next Prime: 21139

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 37 × 571

Divisors: 1, 37, 571, 21127

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001010000111

Octal: 51207

Duodecimal: 10287

Hexadecimal: 5287

Square: 446350129

Square Root: 145.35129858381038

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

Centered icosahedral (or cuboctahedral) numbers, also crystal ball sequence for f.c.c. lattice. A5902

Numbers k > 1 such that, in base 6, k and k² contain the same digits in the same proportion. A61660

Base-3 Keith numbers. A188195

The 360 degree spoke (or ray) of a hexagonal spiral of Ulam. A244803

Number of solutions to c(1)*prime(4) + ... + c(n)*prime(n+3) = 0, where c(i) = +-1 for i>1, c(1) = 1. A22903

Number of finite sets of positive integers whose right half (exclusive) sums to n. A360954

Expansion of (1/x) * Series_Reversion( x*(1+x-x³)/(1+x)² ). A366095

Numbers k whose binary expansion contains 2 adjacent 1's and A391571(k) = k. A391581

Number of (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| + |y-w| >= w + x + y. A213489

Numerators of the partial sums of the reciprocals of the sum of bi-unitary divisors function (A188999). A379615