25618 has 4 divisors (see below), whose sum is σ = 38430. Its totient is φ = 12808.

The previous prime is 25609. The next prime is 25621. The reversal of 25618 is 81652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 23409 + 2209 = 153^2 + 47^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is a plaindrome in base 7, base 12 and base 15.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6403 + ... + 6406.

2²⁵⁶¹⁸ is an apocalyptic number.

25618 is a deficient number, since it is larger than the sum of its proper divisors (12812).

25618 is a wasteful number, since it uses less digits than its factorization.

25618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12811.

The product of its digits is 480, while the sum is 22.

The square root of 25618 is about 160.0562401158. The cubic root of 25618 is about 29.4791579299.

It can be divided in two parts, 2 and 5618, that multiplied together give a square (11236 = 106²).

The spelling of 25618 in words is "twenty-five thousand, six hundred eighteen".