25646 has 4 divisors (see below), whose sum is σ = 38472. Its totient is φ = 12822.

The previous prime is 25643. The next prime is 25657. The reversal of 25646 is 64652.

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

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 pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6410 + ... + 6413.

It is an arithmetic number, because the mean of its divisors is an integer number (9618).

2²⁵⁶⁴⁶ is an apocalyptic number.

25646 is a deficient number, since it is larger than the sum of its proper divisors (12826).

25646 is a wasteful number, since it uses less digits than its factorization.

25646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12825.

The product of its digits is 1440, while the sum is 23.

The square root of 25646 is about 160.1436854828. The cubic root of 25646 is about 29.4898940774.

The spelling of 25646 in words is "twenty-five thousand, six hundred forty-six".