Properties of the Number -7921

Nine Hundred Twenty-One

Basics

Value: -7922 → -7921 → -7920

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 89 ²

Divisors: 1, 89, 7921

Polygonal

Triangular: No

Square: Yes

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

7925 Try Today's Challenge

Representations

Binary: -1111011110001

Octal: -17361

Duodecimal: -4701

Hexadecimal: -1ef1

Square: 62742241

Square Root: 89

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) = ( a(n-1) * a(n-3) + a(n-2) ) / a(n-4), a(1) = a(2) = 1, a(3) = -1, a(4) = -4. A206282

Squares of primes. A1248

Odd squares: a(n) = (2n+1)². Also centered octagonal numbers. A16754

1 and the prime powers p^m where m >= 2, thus excluding the primes. A25475

Prime powers p^e where p is a prime and e >= 2 (prime powers without the primes or 1). A246547

Squared Fibonacci numbers: a(n) = F(n)² where F = A000045. A7598

Numbers whose sum of divisors is prime. A23194

a(n) = a(n-1) + a(n-3) + a(n-4), a(0) = a(1) = a(2) = 1, a(3) = 2. A6498

Numbers of the form p^e where both p and e are prime numbers. A53810

Composite numbers whose prime factors have no digits other than 8 and 9. A36325