25518 has 8 divisors (see below), whose sum is σ = 51048. Its totient is φ = 8504.

The previous prime is 25471. The next prime is 25523. The reversal of 25518 is 81552.

It is a sphenic number, since it is the product of 3 distinct primes.

25518 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 25494 and 25503.

It is a congruent number.

It is an unprimeable number.

25518 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2121 + ... + 2132.

It is an arithmetic number, because the mean of its divisors is an integer number (6381).

2²⁵⁵¹⁸ is an apocalyptic number.

25518 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25524).

25518 is a wasteful number, since it uses less digits than its factorization.

25518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4258.

The product of its digits is 400, while the sum is 21.

The square root of 25518 is about 159.7435444705. The cubic root of 25518 is about 29.4407505618.

The spelling of 25518 in words is "twenty-five thousand, five hundred eighteen".