Properties of the Number 1365

One Thousand Three Hundred Sixty-Five

Basics

Value: 1364 → 1365 → 1366

Parity: odd

Prime: No

Previous Prime: 1361

Next Prime: 1367

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 7 × 13

Divisors: 1, 3, 5, 7, 13, 15, 21, 35, 39, 65

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10101010101

Octal: 2525

Duodecimal: 959

Hexadecimal: 555

Square: 1863225

Square Root: 36.945906403822335

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

Jacobsthal sequence (or Jacobsthal numbers): a(n) = a(n-1) + 2·a(n-2), with a(0) = 0, a(1) = 1; also a(n) = nearest integer to 2ⁿ/3. A1045

a(n) = sigma₂(n): sum of squares of divisors of n. A1157

Binomial coefficient binomial(n,4) = n*(n-1)*(n-2)*(n-3)/24. A332

The squarefree numbers ordered lexicographically by their prime factorization (with factors written in decreasing order). a(n) = ∏_{k in I} prime(k+1), where I is the set of indices of nonzero binary digits in n = ∑_{k in I} 2^k. A19565

a(2n) = 2·a(2n-1), a(2n+1) = 2·a(2n)+1 (also a(n) is the n-th number without consecutive equal binary digits). A975

a(n) = (4ⁿ - 1)/3. A2450

Second pentagonal numbers: a(n) = n*(3·n + 1)/2. A5449

Generalized octagonal numbers: k*(3·k-2), k=0, +- 1, +- 2, +-3, ... A1082

Antisigma(n): Sum of the numbers less than n that do not divide n. A24816

Number of "ON" cells at n-th stage in the "Ulam-Warburton" two-dimensional cellular automaton. A147562