Properties of the Number 20878

Twenty Thousand Eight Hundred Seventy-Eight

Basics

Value: 20877 → 20878 → 20879

Parity: even

Prime: No

Previous Prime: 20873

Next Prime: 20879

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 2 × 11 × 13 × 73

Divisors: 1, 2, 11, 13, 22, 26, 73, 143, 146, 286

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000110001110

Octal: 50616

Duodecimal: 100BA

Hexadecimal: 518e

Square: 435890884

Square Root: 144.49221432312538

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

-2-Knödel numbers. A225506

T(2n+5,n), array T as in A055794. A55798

Number of level steps in all 2-Motzkin paths (i.e., Motzkin paths with blue and red level steps) of length n, without red level steps on the x-axis. A126223

Number of set partitions of [n] such that each block has at most one odd element. A363430

Number of Motzkin excursions of length n with an odd number of peaks. A307578

Expansion of (1-x)^-1/(1-x+2·x²). A77876

Number of permutations of [n] avoiding the pattern 12-3-4. A200406

Determinant of n X n Hankel matrix whose entries are 1-A010060(i+j), where A010060 is the Thue-Morse sequence. A274330

Array, read by antidiagonals, where A(n,k) = exp(-1)*∑_i>=0 (i+k)ⁿ/i!. A108087

Number of maximum matchings in the n-Moebius ladder M_n. A20878