Properties of the Number 20080

Twenty Thousand Eighty

Basics

Value: 20079 → 20080 → 20081

Parity: even

Prime: No

Previous Prime: 20071

Next Prime: 20089

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 2 ⁴ × 5 × 251

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111001110000

Octal: 47160

Duodecimal: B754

Hexadecimal: 4e70

Square: 403206400

Square Root: 141.7039166713468

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 m such that φ(m) = τ(m)³. A68559

Number of rooted trees with n points and exactly k specified colors: C(n,k), 1<=n, 1<=k<=n. A141610

Expansion of e.g.f. 1 / (1 + 5·log(1-x)). A365588

G.f.: 1/(1 + x - x² - x³ + x⁴). A199803

Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. 1/(1 + k·log(1 - x)). A320079

A Moessner triangle using (1, 2, 1, 2, 1, 2, ...). A125751

Lesser of a pair of amicable numbers k < m such that s(k) = m and s(m) = k, where s(k) = A162296(k) - k is the sum of aliquot divisors of k that have a square factor. A357495

G.f. is ((1-x)/(1-2·x)) * G(x*(1-x)/(1-2·x)) where G(x) is g.f. for Catalan numbers A000108. A59279

Triangle read by rows: T(n, k) = qStirling1(n, k, q) for q = 2, with 0 <= k <= n. A333142

Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 21 (most significant digit on right). A29514