Properties of the Number -25

Twenty-Five

Basics

Value: -26 → -25 → -24

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 7

Digital Root: 7

Palindrome: No

Factorization: 5 ²

Divisors: 1, 5, 25

Polygonal

Triangular: No

Square: Yes

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -11001

Octal: -31

Duodecimal: -21

Hexadecimal: -19

Square: 625

Square Root: 5

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

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

Canonical enumeration of integers: interleaved positive and negative integers with zero prepended. A1057

Expansion of q^1/24 * η(q) / η(q²) in powers of q. A81362

a(0) = 0; thereafter a(n) is the least integer (in absolute value) not yet in the sequence such that the absolute difference between a(n-1) and a(n) is a square; in case of a tie, preference is given to the positive value. A377091

a(n) = 2 - n. A22958

Balanced ternary enumeration (based on balanced ternary representation) of integers; write n in ternary and then replace 2's with (-1)'s. A117966

a(n) = A003961(n) - 2·n. A252748

Euler transform of negative integers. A73592

a(0)=0; thereafter a(2n) = 2a(n), a(2n+1) = -2a(n) + 1. A65620

A permutation of the integers: a(n) = (-1)ⁿ * floor( (n+1)/2 ). A130472

G.f.: ∏_k>=1 1/(1+x^k)^k. A255528