25610661 has 40 divisors (see below), whose sum is σ = 40772160. Its totient is φ = 15985728.

The previous prime is 25610647. The next prime is 25610699. The reversal of 25610661 is 16601652.

It is a happy number.

It is not a de Polignac number, because 25610661 - 2⁶ = 25610597 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25610561) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 109801 + ... + 110033.

It is an arithmetic number, because the mean of its divisors is an integer number (1019304).

Almost surely, 2^25610661 is an apocalyptic number.

It is an amenable number.

25610661 is a deficient number, since it is larger than the sum of its proper divisors (15161499).

25610661 is a wasteful number, since it uses less digits than its factorization.

25610661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 318 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 25610661 is about 5060.6976791743. The cubic root of 25610661 is about 294.7634261506.

Subtracting from 25610661 its reverse (16601652), we obtain a palindrome (9009009).

The spelling of 25610661 in words is "twenty-five million, six hundred ten thousand, six hundred sixty-one".