Properties of the Number 21723

Twenty-One Thousand Seven Hundred Twenty-Three

Basics

Value: 21722 → 21723 → 21724

Parity: odd

Prime: No

Previous Prime: 21713

Next Prime: 21727

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 13 × 557

Divisors: 1, 3, 13, 39, 557, 1671, 7241, 21723

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101010011011011

Octal: 52333

Duodecimal: 106A3

Hexadecimal: 54db

Square: 471888729

Square Root: 147.38724503836823

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

Sum of the second largest parts in the partitions of n into 5 parts. A308826

Triangle read by rows: T(n,r), 0 <= r <= n, is the number of idempotents of rank r in the twisted planar partition monoid PP_n^τ. A289620

a(n) = ∑_i=1..n-1(i^n-2) mod n⁴. A284760

Triangle T(n,k) (n >= 1, 0 <= k <= n-1) read by rows: number of distinct permutations after k steps of the "first transposition" algorithm. A345462

Numbers whose base-7 representation contains exactly four 2's. A43404

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0100-1111 pattern in any orientation. A146654

Table read by rows: T(n, k) = T(n, k-1) + m·T(n-1, n-k) for k > 1, T(n, 1) = T(n-1, n-1), and T(n, 0) = 0ⁿ, for m = 2. A385895

G.f. satisfies: A(x) = 1 + x/A(-x·A(x)¹²)⁶. A213105

G.f. satisfies: A(x) = ∑_n>=0 xⁿ * ∏_k=0..n-1 A(u(n)^k*x), where u(n) = exp(2*π*I/n) is an n-th root of unity. A206725

Number of -n..n arrays of length 7 with the sum ahead of each element differing from the sum following that element by n or less. A221970