Properties of the Number 1915

One Thousand Nine Hundred Fifteen

Basics

Value: 1914 → 1915 → 1916

Parity: odd

Prime: No

Previous Prime: 1913

Next Prime: 1931

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 5 × 383

Divisors: 1, 5, 383, 1915

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11101111011

Octal: 3573

Duodecimal: 1137

Hexadecimal: 77b

Square: 3667225

Square Root: 43.76071297408213

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

a(n) = 4·n² - 9·n + 6. A54556

Number of nonisomorphic semigroups of order n. A27851

a(n) = 2·a(n-1) - 2·a(n-3) + a(n-4) for n > 3, with initial terms 1, 1, 4, 8. A267682

|First digit - second digit + third digit - fourth digit ...| = 12. A60980

3-Bell numbers: E.g.f.: exp(3·z + exp(z) - 1). A5494

Number of ordered triples (a, b, c) with gcd(a, b, c) = 1 and 1 <= {a, b, c} <= n. A71778

Number of Catalan objects of size n fixed by Catalan Automorphism A057511/A057512 (deep rotation of general parenthesizations/plane trees). A57546

Numbers with exactly 9 ones in binary expansion. A23691

a(n) = 1·2 + 3·4 + 5·6 + 7·8 + 9·10 + 11·12 + 13·14 + ... + (up to n). A228958

a(n) = 2·n² + 8·n + 1. A161532