25664261 has 4 divisors (see below), whose sum is σ = 29330592. Its totient is φ = 21997932.

The previous prime is 25664257. The next prime is 25664263. The reversal of 25664261 is 16246652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25664261 - 2² = 25664257 is a prime.

It is a super-2 number, since 2×25664261² = 1317308585352242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25664263) 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, 1833155 + ... + 1833168.

It is an arithmetic number, because the mean of its divisors is an integer number (7332648).

Almost surely, 2^25664261 is an apocalyptic number.

It is an amenable number.

25664261 is a deficient number, since it is larger than the sum of its proper divisors (3666331).

25664261 is an equidigital number, since it uses as much as digits as its factorization.

25664261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3666330.

The product of its digits is 17280, while the sum is 32.

The square root of 25664261 is about 5065.9906237576. The cubic root of 25664261 is about 294.9689175333.

The spelling of 25664261 in words is "twenty-five million, six hundred sixty-four thousand, two hundred sixty-one".