Properties of the Number 31405

Thirty-One Thousand Four Hundred Five

Basics

Value: 31404 → 31405 → 31406

Parity: odd

Prime: No

Previous Prime: 31397

Next Prime: 31469

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 5 × 11 × 571

Divisors: 1, 5, 11, 55, 571, 2855, 6281, 31405

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111101010101101

Octal: 75255

Duodecimal: 16211

Hexadecimal: 7aad

Square: 986274025

Square Root: 177.21455922130102

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

Triangle T(n, k) read by rows; given by [1, 1, 1, 1, 1, ...] δ [1, 1, 2, 5, 14, 42, 132, 429, 1430, ...] (A000108) where δ is Deléham's operator defined in A084938. A85843

Expansion of ∑_k>=2 x^Fibonacci(k)/(1 - x^Fibonacci(k)) / ∏_k>=2 (1 - x^Fibonacci(k)). A281689

a(n) = DP(n) is the total number of k-double-palindromes of n, where 2 <= k <= n. A180750

Second column of the triangle A085843. A261048

Numbers k such that the continued fraction for sqrt(k) has even period 2·m and the m-th term of the periodic part is 2. A31405