25643887 has 4 divisors (see below), whose sum is σ = 25660096. Its totient is φ = 25627680.

The previous prime is 25643879. The next prime is 25643897. The reversal of 25643887 is 78834652.

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

It is a cyclic number.

It is not a de Polignac number, because 25643887 - 2³ = 25643879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25643897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5439 + ... + 8992.

It is an arithmetic number, because the mean of its divisors is an integer number (6415024).

Almost surely, 2^25643887 is an apocalyptic number.

25643887 is a deficient number, since it is larger than the sum of its proper divisors (16209).

25643887 is a wasteful number, since it uses less digits than its factorization.

25643887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16208.

The product of its digits is 322560, while the sum is 43.

The square root of 25643887 is about 5063.9793640970. The cubic root of 25643887 is about 294.8908415437.

The spelling of 25643887 in words is "twenty-five million, six hundred forty-three thousand, eight hundred eighty-seven".