25664891 has 4 divisors (see below), whose sum is σ = 29331312. Its totient is φ = 21998472.

The previous prime is 25664887. The next prime is 25664923. The reversal of 25664891 is 19846652.

It is a happy number.

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 25664891 - 2² = 25664887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25634891) 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, 1833200 + ... + 1833213.

It is an arithmetic number, because the mean of its divisors is an integer number (7332828).

Almost surely, 2^25664891 is an apocalyptic number.

25664891 is a deficient number, since it is larger than the sum of its proper divisors (3666421).

25664891 is an equidigital number, since it uses as much as digits as its factorization.

25664891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3666420.

The product of its digits is 103680, while the sum is 41.

The square root of 25664891 is about 5066.0528027252. The cubic root of 25664891 is about 294.9713311219.

The spelling of 25664891 in words is "twenty-five million, six hundred sixty-four thousand, eight hundred ninety-one".