Properties of the Number 11815

Eleven Thousand Eight Hundred Fifteen

Basics

Value: 11814 → 11815 → 11816

Parity: odd

Prime: No

Previous Prime: 11813

Next Prime: 11821

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 5 × 17 × 139

Divisors: 1, 5, 17, 85, 139, 695, 2363, 11815

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10111000100111

Octal: 27047

Duodecimal: 6A07

Hexadecimal: 2e27

Square: 139594225

Square Root: 108.69682608061746

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

23-gonal numbers: a(n) = n(21n-19)/2. A51875

Number of partitions of n such that the number of odd parts is a part. A240574

Odd composite integers m such that A004254(m-J(m,21)) == 0 (mod m) and gcd(m,21)=1, where J(m,21) is the Jacobi symbol. A340098

Pair the odd numbers such that the k-th pair is (r, r+2k) where r is the smallest odd number not included earlier: (1, 3), (5, 9), (7, 13), (11, 19), (15, 25), (17, 29), (21, 35), (23, 39), (27, 45), ... This is the sequence of the product of the members of pairs. A75320

Number of orbits of the 4-step recursion mod n. A106286

Number of partitions p of n such that (number of distinct parts of p) >= max(p) - min(p). A239958

Odd composite integers m such that A003501(2·m-J(m,21)) == 5 (mod m) and gcd(m,21)=1, where J(m,21) is the Jacobi symbol. A339522

Triangle read by rows: T(n,k) is the number of oriented graphs on n unlabeled nodes with k arcs, n >= 0, k = 0..n*(n-1)/2. A350733

a(1)=5; thereafter, if n odd, a(n) = a(n-1)-st prime, and if n even, a(n) = a(n-1)-st nonprime. A280030

Number of (w,x,y) with all terms in {0,...,n} and w<x+y and x<y. A212980