Properties of the Number 31687

Thirty-One Thousand Six Hundred Eighty-Seven

Basics

Value: 31686 → 31687 → 31688

Parity: odd

Prime: Yes

Previous Prime: 31667

Next Prime: 31699

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 31687

Divisors: 1, 31687

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111101111000111

Octal: 75707

Duodecimal: 16407

Hexadecimal: 7bc7

Square: 1004065969

Square Root: 178.00842676682473

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 read by rows: T(n,k) (1 <= k <= n) = number of monomer-dimer tilings of an n X k board. A210662

Primes of the form k² + 3. A49423

Number of matchings in graph P₃ X P_n. A33506

Number of matchings in graph P₆ X P_n. A33509

In the '3x+1' problem, primes which as starting values set new records for number of steps to reach 1, where a step means either 'divide by two' or 'triple plus one and then divide by two'. A244638

Let n range through the odd numbers skipping multiples of 5; a(n) = n-th prime ending in n. A89779

a(n) is the first prime p such that the sum of 2·n consecutive primes starting at p is (q-1)*q where q is prime, or 0 if there is no such p. A338990

Duplicate of A049423. A121825

Primes p such that 2p + 3, 4p + 9, 3p + 2 and 9p + 8 are also primes. A176619

Number of fixed tree-like convex polyominoes. A196593