Properties of the Number 20913

Twenty Thousand Nine Hundred Thirteen

Basics

Value: 20912 → 20913 → 20914

Parity: odd

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 6971

Divisors: 1, 3, 6971, 20913

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101000110110001

Octal: 50661

Duodecimal: 10129

Hexadecimal: 51b1

Square: 437353569

Square Root: 144.61327739872297

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

G.f.: A(x) = 1+x*(1+x*(1+x*(...(1+x*(...)ⁿ)...)³)²)¹. A95793

G.f. satisfies A(x) = 1 + x·A(x)² + x³*A(x)⁵. A216490

Number of partitions of n into 8 or more parts. A347544

Numbers·such that σ(x) + σ(R(x)) = σ(x + R(x)), where R(x) is the digit reversal of·and σ(x) is the sum of the divisors of x. A246487

tanh(arcsin(arctanh(x)))=x+1/3!*x³+9/5!*x⁵+281/7!*x⁷+20913/9!*x⁹... A12141

Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 96. A31594

Numbers whose base-12 representation has exactly 5 runs. A43654

Number of terms in base 5 representation of Fibonacci(n). A20913

Regular triangular array read by rows: T(n,m) = π(n·m) - π(n)*π(m) for n > 0 and 0 < m <= n. A294508