Properties of the Number 31920

Thirty-One Thousand Nine Hundred Twenty

Basics

Value: 31919 → 31920 → 31921

Parity: even

Prime: No

Previous Prime: 31907

Next Prime: 31957

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 ⁴ × 3 × 5 × 7 × 19

Divisors: 1, 2, 3, 4, 5, 6, 7, 8, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111110010110000

Octal: 76260

Duodecimal: 16580

Hexadecimal: 7cb0

Square: 1018886400

Square Root: 178.66169147301835

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

Triangular array a(n,k) = (1/k)*∑_i=0..k (-1)^k-i*binomial(k,i)*iⁿ; n >= 1, 1 <= k <= n, read by rows. A28246

Triangle read by rows: The n-th derivative of the logistic function written in terms of y, where y = 1/(1 + exp(-x)). A163626

Let a,b,c,...k be all divisors of n; a(n) = (a+1)*(b+1)*...*(k+1). A20696

a(n) = (3·n+4)*(n+3)!/24. A5460

Triangle read by rows, 0 <= k <= n, T(n,k) = ∑_j=0..n A(n,j)*binomial(n-j,k) where A(n,j) are the Eulerian numbers A173018. A130850

Numbers n such that the multiplicative group modulo n is the direct product of 6 cyclic groups. A272596

Numbers k which have a factorization k = f1·f2*...*fr where the digits of {k, f1, f2, ..., fr} together give 0,1,...,9 exactly once. A370970

Number of ways to partition n labeled elements into 6 pie slices. A32180

Triangle of coefficients of polynomials H(n,x) formed from the first (n+1) terms of the power series expansion of ( -x/log(1-x) )ⁿ⁺¹, multiplied by n!. A75263

Numbers with prime factorization p·q*r·s*t⁴ (where p, q, r, s, t are distinct primes). A190110