25640978 has 16 divisors (see below), whose sum is σ = 42042240. Its totient is φ = 11631600.

The previous prime is 25640977. The next prime is 25640983. The reversal of 25640978 is 87904652.

It is not an unprimeable number, because it can be changed into a prime (25640977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15008 + ... + 16628.

It is an arithmetic number, because the mean of its divisors is an integer number (2627640).

Almost surely, 2^25640978 is an apocalyptic number.

25640978 is a deficient number, since it is larger than the sum of its proper divisors (16401262).

25640978 is a wasteful number, since it uses less digits than its factorization.

25640978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 25640978 is about 5063.6921312418. The cubic root of 25640978 is about 294.8796904794.

The spelling of 25640978 in words is "twenty-five million, six hundred forty thousand, nine hundred seventy-eight".