25165621 has 12 divisors (see below), whose sum is σ = 27892128. Its totient is φ = 22683024.

The previous prime is 25165603. The next prime is 25165639. The reversal of 25165621 is 12656152.

It is an interprime number because it is at equal distance from previous prime (25165603) and next prime (25165639).

It is not a de Polignac number, because 25165621 - 2⁹ = 25165109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25165621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25165421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5536 + ... + 8998.

It is an arithmetic number, because the mean of its divisors is an integer number (2324344).

Almost surely, 2^25165621 is an apocalyptic number.

It is an amenable number.

25165621 is a deficient number, since it is larger than the sum of its proper divisors (2726507).

25165621 is a wasteful number, since it uses less digits than its factorization.

25165621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3532 (or 3519 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 25165621 is about 5016.5347601706. The cubic root of 25165621 is about 293.0460581379.

The spelling of 25165621 in words is "twenty-five million, one hundred sixty-five thousand, six hundred twenty-one".