Properties of the Number 21676

Twenty-One Thousand Six Hundred Seventy-Six

Basics

Value: 21675 → 21676 → 21677

Parity: even

Prime: No

Previous Prime: 21673

Next Prime: 21683

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 2 ² × 5419

Divisors: 1, 2, 4, 5419, 10838, 21676

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010010101100

Octal: 52254

Duodecimal: 10664

Hexadecimal: 54ac

Square: 469848976

Square Root: 147.22771478223794

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

Triangle read by rows: T(n,k) is the number of up-down permutations of {1,2,...,n} having genus k (see first comment for definition of genus). A178516

Numbers k such that 17·2^k - 1 is prime. A1774

Positive integers that have exactly ten representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes. A317400

Base-2 logarithm of (n-th even superperfect number divided by 2ⁿ), plus 1. A134713

Numbers k such that k!!! - 3^k is prime. A261316

Expansion of (1+3·x²+7·x³+15·x⁴+13·x⁵+15·x⁶+8·x⁷+4·x⁸)/((1-x)*(1-x²)³*(1-x³)²). A37241

Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 50. A156512

Smallest primes of the form (i+1)(i+2)...(h-1)(h)1234...(i-1)(i). These elements, by definition, belong to A001292. A181129

Number of nX5 binary arrays without the pattern 0 1 0 antidiagonally or horizontally. A189060

Number of 5Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 5 neighboring 1s. A297598