25640985 has 16 divisors (see below), whose sum is σ = 41100480. Its totient is φ = 13650240.

The previous prime is 25640983. The next prime is 25641047. The reversal of 25640985 is 58904652.

It is not a de Polignac number, because 25640985 - 2¹ = 25640983 is a prime.

It is a super-2 number, since 2×25640985² = 1314920223540450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25640983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9430 + ... + 11840.

It is an arithmetic number, because the mean of its divisors is an integer number (2568780).

Almost surely, 2^25640985 is an apocalyptic number.

It is an amenable number.

25640985 is a deficient number, since it is larger than the sum of its proper divisors (15459495).

25640985 is a wasteful number, since it uses less digits than its factorization.

25640985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3128.

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

The square root of 25640985 is about 5063.6928224370. The cubic root of 25640985 is about 294.8797173135.

The spelling of 25640985 in words is "twenty-five million, six hundred forty thousand, nine hundred eighty-five".