Properties of the Number 31686

Thirty-One Thousand Six Hundred Eighty-Six

Basics

Value: 31685 → 31686 → 31687

Parity: even

Prime: No

Previous Prime: 31667

Next Prime: 31687

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 5281

Divisors: 1, 2, 3, 6, 5281, 10562, 15843, 31686

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111101111000110

Octal: 75706

Duodecimal: 16406

Hexadecimal: 7bc6

Square: 1004002596

Square Root: 178.0056178888745

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

G.f.: A(x) = ∑_n>=0 xⁿ / ∏_k=1..n (1 - k·x^k). A193196

Linear recurrence sequence with infrequent pseudoprimes, a(n) = -a(n-1) + a(n-2) - a(n-3) + a(n-5), with initial terms (5, -1, 3, -7, 11). A225984

Assume the conjectured terms of A105594 are the correct beginnings of the trajectories described in A003508. a(n) is a record length of b(n) iterations to arrive at the collected trajectories. This sequence cites the a(n)'s. A105600

Becomes prime or 4 after exactly 9 iterations of f(x) = sum of prime factors of x. A48131

a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (1, p(1), p(2), ...), t = (composite numbers). A25100

a(n) = (4ⁿ - 1)/3. A2450

Triangle read by rows giving successive states of cellular automaton generated by "Rule 50". A71028

Number of (n+1)X(2+1) 0..2 arrays with no 2X2 subblock having its minimum diagonal element less than its minimum antidiagonal element. A250921

Triangle read by rows in which row n >= 1 lists the count of 0's, ..., k's in all previous terms in the triangle. T(0,0) = 0, k is from [0..A049820(n)]. A349042

Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 98. A31686