Properties of the Number 81313

Eighty-One Thousand Three Hundred Thirteen

Basics

Value: 81312 → 81313 → 81314

Parity: odd

Prime: No

Previous Prime: 81307

Next Prime: 81331

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 31 × 43 × 61

Divisors: 1, 31, 43, 61, 1333, 1891, 2623, 81313

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110110100001

Octal: 236641

Duodecimal: 3B081

Hexadecimal: 13da1

Square: 6611803969

Square Root: 285.15434417171343

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

Number of pairs with two different elements which can be obtained by selecting unique elements from two sets with n+1 and n² elements respectively and n common elements. A85490

E.g.f.: exp(x * ∏_k>0 (1 + x^k)). A293528

First appearance of n in A016014, or 0 if n never occurs. A239800

Number of non-congruent solutions of x²+y² == z²+w² (mod n). A316148

Let q be the n-th prime power (A246655), then a(n) = q³ + q² - q; number of solutions to x·y = z·w in the finite field F_q. A367014

a(n) is the genus of the modular curve associated to the principal congruence subgroup of level p(n), where p(n) is the n-th prime number. A191590

a(n) = (n + 1)*(2·n + 1)*(4·n + 9)/3. A269342

Numbers having more than one representation as sum of a prime and a 3-smooth number. A81313