Properties of the Number 21092

Twenty-One Thousand Ninety-Two

Basics

Value: 21091 → 21092 → 21093

Parity: even

Prime: No

Previous Prime: 21089

Next Prime: 21101

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 ² × 5273

Divisors: 1, 2, 4, 5273, 10546, 21092

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001001100100

Octal: 51144

Duodecimal: 10258

Hexadecimal: 5264

Square: 444872464

Square Root: 145.23085071705668

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 permutations of {1,2,...,n} having k nonincreasing even cycles (0<=k<=floor(n/4)). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be even if it has an even number of entries. For example, the permutation (1528)(347)(6) has 1 nonincreasing even cycles. A186769

Number of integer partitions of n whose run-sums are not weakly decreasing. A357878

Number of 2-sided strip polyrects with n cells. A151527

Number of permutations of {1,2,...,n} having no nonincreasing even cycles. A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be even if it has an even number of entries. A186770

Number of primitive (aperiodic) palindromic structures of length n using an infinite alphabet. A284841

a(n) = floor(product of next n primes / product of next n composite numbers). A77145

Number of different values assumed by a/b+c/d as a,b,c,d range between 1 and n. A119868

Expansion of ∏_{i>=1, j>=1} theta₃(x^i·j), where theta₃() is the Jacobi θ function. A308286

Intersection of A361073 and 2·A361611. A361215

Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4. A241430