Properties of the Number 21261

Twenty-One Thousand Two Hundred Sixty-One

Basics

Value: 21260 → 21261 → 21262

Parity: odd

Prime: No

Previous Prime: 21247

Next Prime: 21269

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 19 × 373

Divisors: 1, 3, 19, 57, 373, 1119, 7087, 21261

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001100001101

Octal: 51415

Duodecimal: 10379

Hexadecimal: 530d

Square: 452030121

Square Root: 145.81152217846162

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) = 2·n³ - 2·n + 9. A127989

Number of (w,x,y) with all terms in {0,...,n} and w<x+y and x<=y. A212982

One seventh of the sum of the first n primes, when an integer. A112272

G.f. A(x) satisfies: 0 = ∑_n=-oo..+oo x^n*(n-1/2) * (xⁿ - A(x))ⁿ. A355861

Number of nX3 0..1 arrays with no more than floor(nX3/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order. A222355

Base-8 palindromes that start with 5. A43025

T(n,k)=Number of nXk 0..1 arrays with no more than floor(nXk/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order. A222360

Nonnegative integers k such that (R(k) - 1)/(k + 1) is an integer, where R(k) is the digit reversal of k. A367593

Decimal expansion of 1/257. A21261