Properties of the Number 3921

Three Thousand Nine Hundred Twenty-One

Basics

Value: 3920 → 3921 → 3922

Parity: odd

Prime: No

Previous Prime: 3919

Next Prime: 3923

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 1307

Divisors: 1, 3, 1307, 3921

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 111101010001

Octal: 7521

Duodecimal: 2329

Hexadecimal: f51

Square: 15374241

Square Root: 62.617888817813075

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 3 X 3 X 3 arrays M_ijk (1 <= i,j,k <= 3) with entries satisfying 0 <= M_ijk <= n and all line sums equal to n. A2721

Main diagonal of A277320: a(n) = A048720(n, A065621(n)). A277699

a(1) = 8; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime. A74344

a(n) = ∑_k=1..n floor(n/k)³. A318742

Number of integer partitions of n where the parts have lesser mean than the distinct parts. A360251

T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock summing to 3 4 or 5. A251351

Integers that are squarefree and also the sum of first k squarefrees for some k. A13932

a(n) = ∑_k=0..n C(n,3k)². A119363

Square table defined by T(n,k) = ∑_{m=k(k+1)/2..k(k+1)/2+k} [x^m] S(x)ⁿ for n>=1, k>=0, where S(x) = ∑_n>=0 xⁿ⁽ⁿ⁺¹/2), as read by antidiagonals. A162430

Main diagonal of table A162430. A162435