Properties of the Number 31985

Thirty-One Thousand Nine Hundred Eighty-Five

Basics

Value: 31984 → 31985 → 31986

Parity: odd

Prime: No

Previous Prime: 31981

Next Prime: 31991

Digit Sum: 26

Digital Root: 8

Palindrome: No

Factorization: 5 × 6397

Divisors: 1, 5, 6397, 31985

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 111110011110001

Octal: 76361

Duodecimal: 16615

Hexadecimal: 7cf1

Square: 1023040225

Square Root: 178.84350701101786

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

T(n,k)=Number of nXk 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1s. A295716

Number of primes of the form P(k) = k² + k + 41 for k <= 10ⁿ, where P(k) is Euler's prime-generating polynomial A202018. A331876

Number of subsets of {1, ..., n} that are double-free or sum-free. A88813

Number of prime numbers of the form k² + k + 41 below 10ⁿ. A319906

Number of runs of 0's of odd length in all ternary words of length n. A119916

a(n) = ∑_{k = 1..10ⁿ} number of primes (counted with multiplicity) dividing k (A001222). A71811

Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1s. A295712

Number of n X n 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1's. A295710

Numbers n such that n² + n + 41 (known as Euler's polynomial) is prime. A56561

Numbers with exactly five distinct base-8 digits. A31985