25641 has 24 divisors (see below), whose sum is σ = 47424. Its totient is φ = 12960.

The previous prime is 25639. The next prime is 25643. The reversal of 25641 is 14652.

It is a happy number.

25641 is a `hidden beast` number, since 25 + 641 = 666.

25641 is nontrivially palindromic in base 6.

It is an interprime number because it is at equal distance from previous prime (25639) and next prime (25643).

It is not a de Polignac number, because 25641 - 2¹ = 25639 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 675 + ... + 711.

It is an arithmetic number, because the mean of its divisors is an integer number (1976).

2²⁵⁶⁴¹ is an apocalyptic number.

25641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25641 is a deficient number, since it is larger than the sum of its proper divisors (21783).

25641 is a wasteful number, since it uses less digits than its factorization.

25641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61 (or 58 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 25641 is about 160.1280737410. The cubic root of 25641 is about 29.4879774815.

It can be divided in two parts, 25 and 641, that added together give a palindrome (666).

The spelling of 25641 in words is "twenty-five thousand, six hundred forty-one".