Properties of the Number 3991

Three Thousand Nine Hundred Ninety-One

Basics

Value: 3990 → 3991 → 3992

Parity: odd

Prime: No

Previous Prime: 3989

Next Prime: 4001

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 13 × 307

Divisors: 1, 13, 307, 3991

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111110010111

Octal: 7627

Duodecimal: 2387

Hexadecimal: f97

Square: 15928081

Square Root: 63.17436188834834

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

Number of sublattices of index n in generic 3-dimensional lattice. A1001

Number of integer partitions of n with no part dividing all the others. A338470

Numbers m > 1 such that a record number of numbers k have m as the sum of the proper divisors of k. A238895

Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,k+n} having excedance set {1,2,...,k} (the empty set for k=0), 0 <= k <= n-1. A136126

a(n) = 2·3ⁿ - 3·2ⁿ + 1. A91344

Number of labeled graded partially ordered sets with n elements. A1833

Rounded total surface area of a regular tetrahedron with edge length n. A70169

First term of the n-th differences of the squarefree numbers. Inverse zero-based binomial transform of A005117. A377041

a(n) = 1 + n*(n+1)*(n-1)/2. A158842

Concentric 19-gonal numbers. A195048