640366250 has 40 divisors (see below), whose sum is σ = 1204489440. Its totient is φ = 255254000.

The previous prime is 640366231. The next prime is 640366261. The reversal of 640366250 is 52663046.

640366250 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 448037 + ... + 449463.

It is an arithmetic number, because the mean of its divisors is an integer number (30112236).

Almost surely, 2^640366250 is an apocalyptic number.

640366250 is a deficient number, since it is larger than the sum of its proper divisors (564123190).

640366250 is a wasteful number, since it uses less digits than its factorization.

640366250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1808 (or 1793 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 640366250 is about 25305.4588972419. The cubic root of 640366250 is about 861.9382325201.

The spelling of 640366250 in words is "six hundred forty million, three hundred sixty-six thousand, two hundred fifty".