Properties of the Number 20730

Twenty Thousand Seven Hundred Thirty

Basics

Value: 20729 → 20730 → 20731

Parity: even

Prime: No

Previous Prime: 20719

Next Prime: 20731

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 5 × 691

Divisors: 1, 2, 3, 5, 6, 10, 15, 30, 691, 1382

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000011111010

Octal: 50372

Duodecimal: BBB6

Hexadecimal: 50fa

Square: 429732900

Square Root: 143.9791651594077

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

T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock sum of the medians of the diagonal and antidiagonal minus the two sums of the central row and column nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A255756

T(n, 2·n-3), T given by A027960. A27965

Principal diagonal of the convolution array A213778. A213779

Number of partitions of (2, n) into a sum of distinct pairs. A268345

Coefficient of·in the reduction by x²->x+1 of the polynomial p(n,x) defined below in Comments. A192758

Related to population of numbers of form x² + y². A709

Number of rooted trees with n nodes and 6 leaves. A55281

a(n) = 36·n² - 6. A158462

Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock sum of the medians of the diagonal and antidiagonal minus the two sums of the central row and column nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A255750

Number of (3+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the medians of the diagonal and antidiagonal minus the two sums of the central row and column nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A255758