Properties of the Number 81406

Eighty-One Thousand Four Hundred Six

Basics

Value: 81405 → 81406 → 81407

Parity: even

Prime: No

Previous Prime: 81401

Next Prime: 81409

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 × 13 × 31 × 101

Divisors: 1, 2, 13, 26, 31, 62, 101, 202, 403, 806

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110111111110

Octal: 236776

Duodecimal: 3B13A

Hexadecimal: 13dfe

Square: 6626936836

Square Root: 285.31736715454247

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

Numbers of the form prime(n) + prime(n+1) - 2 that are also triangular numbers, T(k) = k(k+1)/2. A110891

Smallest triangular number whose decimal expansion ends (nontrivially) with the n-th triangular number. A229262

Numbers that start a run of four consecutive triangular numbers with four distinct prime factors. A349773

Triangular numbers all of whose digits are nonprimes. A111484

Hexagonal numbers that are products of exactly four distinct primes. A381920

Numbers n having at least two distinct symmetrical pairs of divisors (a, b) and (b', a') such that n = a·b = b'*a' with a' = reverse(a) and b' = reverse(b). A228164

a(n) = (n+1)*a(n-3), a(0)=a(1)=a(2)=1 for n>1. A81406