Properties of the Number 21641

Twenty-One Thousand Six Hundred Forty-One

Basics

Value: 21640 → 21641 → 21642

Parity: odd

Prime: No

Previous Prime: 21617

Next Prime: 21647

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 17 × 19 × 67

Divisors: 1, 17, 19, 67, 323, 1139, 1273, 21641

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010010001001

Octal: 52211

Duodecimal: 10635

Hexadecimal: 5489

Square: 468332881

Square Root: 147.10880327159214

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

Numbers which converge to 2592 under repeated application of the powertrain map of A133500. A135384

Numbers k that divide the sum of digits of 13^k. A175525

Positive integers of the form (18·m²+1)/11. A113338

Expansion of (1-x)/(1-2·x-x²-2·x³). A77996

Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 533", based on the 5-celled von Neumann neighborhood. A282957

Numbers n such that A003146(n) = floor(α³*n)+1, where α = 1.839... is the positive real zero of x³-x²-x-1. A278353

Numbers n with property that for each single digit d of n, we can also see the decimal expansion of 2^d as a substring of n. Also n may not contain any zero digits. A135016

Nonsemiprimes in A306097 = A121707 \ A267999. A321488

Number of 5X2 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2·n² (number of collections of 5 zero-sum 2-vectors with total modulus squared not more than 2·n², ignoring vector and component permutations). A192705

Nonsquare factors k > 0 such that k·x² - 1 produces a new minimum of its Hardy-Littlewood constant. A331948