25365721 has 4 divisors (see below), whose sum is σ = 25457572. Its totient is φ = 25273872.

The previous prime is 25365709. The next prime is 25365727. The reversal of 25365721 is 12756352.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13220496 + 12145225 = 3636^2 + 3485^2 .

It is a cyclic number.

It is not a de Polignac number, because 25365721 - 2²³ = 16977113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25365727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45510 + ... + 46063.

It is an arithmetic number, because the mean of its divisors is an integer number (6364393).

Almost surely, 2^25365721 is an apocalyptic number.

It is an amenable number.

25365721 is a deficient number, since it is larger than the sum of its proper divisors (91851).

25365721 is an equidigital number, since it uses as much as digits as its factorization.

25365721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91850.

The product of its digits is 12600, while the sum is 31.

The square root of 25365721 is about 5036.4393176132. The cubic root of 25365721 is about 293.8207099432.

The spelling of 25365721 in words is "twenty-five million, three hundred sixty-five thousand, seven hundred twenty-one".