25685661 has 4 divisors (see below), whose sum is σ = 34247552. Its totient is φ = 17123772.

The previous prime is 25685633. The next prime is 25685713. The reversal of 25685661 is 16658652.

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 not a de Polignac number, because 25685661 - 2⁵ = 25685629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25685461) 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, 4280941 + ... + 4280946.

It is an arithmetic number, because the mean of its divisors is an integer number (8561888).

Almost surely, 2^25685661 is an apocalyptic number.

It is an amenable number.

25685661 is a deficient number, since it is larger than the sum of its proper divisors (8561891).

25685661 is an equidigital number, since it uses as much as digits as its factorization.

25685661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8561890.

The product of its digits is 86400, while the sum is 39.

The square root of 25685661 is about 5068.1023075704. The cubic root of 25685661 is about 295.0508808148.

The spelling of 25685661 in words is "twenty-five million, six hundred eighty-five thousand, six hundred sixty-one".