Properties of the Number 3980

Three Thousand Nine Hundred Eighty

Basics

Value: 3979 → 3980 → 3981

Parity: even

Prime: No

Previous Prime: 3967

Next Prime: 3989

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 ² × 5 × 199

Divisors: 1, 2, 4, 5, 10, 20, 199, 398, 796, 995

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111110001100

Octal: 7614

Duodecimal: 2378

Hexadecimal: f8c

Square: 15840400

Square Root: 63.08724118235002

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

a(n) = (-6·n⁷ + 154·n⁶ - 1533·n⁵ + 7525·n⁴ - 18879·n³ + 22561·n² - 7302·n + 2520)/2520. A161710

a(n) = floor(n*φ¹¹), where φ is the golden ratio, A001622. A4926

The q expansion of λ⁵, a Hauptmodul for Gamma₁(5). A78905

Smallest multiple of n whose digits sum to n. A2998

a(n) = ∑_k=0..n-2 T(n,k) * T(n,k+2), with T given by A026626. A26963

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. A258554

a(n) = (-1)ⁿ * ∑_k=0..n Stirling1(n,k) * Stirling1(n,n-k). A342111

Number of parity preserving permutations of the set {1,2,...,n} with exactly k cycles. A246117

a(n) = ∑_{r = 0 to n} L(n,r), where L(n,r) (A067049) = lcm(n, n-1, n-2, ..., n-r+1)/lcm(1, 2, 3, ..., r). A61297

Number of 7-line partitions of n (i.e., planar partitions of n with at most 7 lines). A225197