Properties of the Number 1918

One Thousand Nine Hundred Eighteen

Basics

Value: 1917 → 1918 → 1919

Parity: even

Prime: No

Previous Prime: 1913

Next Prime: 1931

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 × 7 × 137

Divisors: 1, 2, 7, 14, 137, 274, 959, 1918

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: Yes

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 11101111110

Octal: 3576

Duodecimal: 113A

Hexadecimal: 77e

Square: 3678724

Square Root: 43.79497688091638

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

Heptagonal numbers (or 7-gonal numbers): n*(5·n-3)/2. A566

Regular triangle read rows: T(n,k) = number of non-isomorphic multiset partitions of size n and length k. A317533

Numbers k such that 10^2·k+1-7·10^k-1 is prime. A115073

T(n,m) = number of 0..m-1 integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1. A171307

Triangle T(n,k) of associated Stirling numbers of second kind, n >= 2, 1 <= k <= floor(n/2). A8299

Triangle T read by rows: diagonal differences of triangle A037027. A55830

Numbers k such that the largest prime factor of k²-1 is 101. A181568

a(n) = -2·n² + 12·n - 14. A147973

Triangle of Ward numbers T(n,k) read by rows. A134991

a(1)=1, for n>1, a(n) is the least number > a(n-1) such that the Hamming distance D(a(n-1), a(n)) = 2. A206853