25640218 has 16 divisors (see below), whose sum is σ = 39060000. Its totient is φ = 12622032.

The previous prime is 25640213. The next prime is 25640221. The reversal of 25640218 is 81204652.

It is not an unprimeable number, because it can be changed into a prime (25640213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41113 + ... + 41731.

It is an arithmetic number, because the mean of its divisors is an integer number (2441250).

Almost surely, 2^25640218 is an apocalyptic number.

25640218 is a deficient number, since it is larger than the sum of its proper divisors (13419782).

25640218 is a wasteful number, since it uses less digits than its factorization.

25640218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 25640218 is about 5063.6170866289. The cubic root of 25640218 is about 294.8767770339.

The spelling of 25640218 in words is "twenty-five million, six hundred forty thousand, two hundred eighteen".