Properties of the Number 39981

Thirty-Nine Thousand Nine Hundred Eighty-One

Basics

Value: 39980 → 39981 → 39982

Parity: odd

Prime: No

Previous Prime: 39979

Next Prime: 39983

Digit Sum: 30

Digital Root: 3

Palindrome: No

Factorization: 3 × 13327

Divisors: 1, 3, 13327, 39981

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 1001110000101101

Octal: 116055

Duodecimal: 1B179

Hexadecimal: 9c2d

Square: 1598480361

Square Root: 199.95249435803495

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

T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 8 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 8. A252334

Semiprimes q such that q²-4 and q²+4 are also semiprimes. A173084

Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 8 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 8. A252327

Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 8 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 8. A252332

An example of a d-perfect sequence. A39981

Record values obtained in the iterative process related to the abundancy function σ(n)/n described in comments. A247141