640250566 has 16 divisors (see below), whose sum is σ = 1021321440. Its totient is φ = 299975040.

The previous prime is 640250551. The next prime is 640250641. The reversal of 640250566 is 665052046.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33330 + ... + 48901.

It is an arithmetic number, because the mean of its divisors is an integer number (63832590).

Almost surely, 2^640250566 is an apocalyptic number.

640250566 is a deficient number, since it is larger than the sum of its proper divisors (381070874).

640250566 is a wasteful number, since it uses less digits than its factorization.

640250566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82479.

The product of its (nonzero) digits is 43200, while the sum is 34.

The square root of 640250566 is about 25303.1730421305. The cubic root of 640250566 is about 861.8863255229.

The spelling of 640250566 in words is "six hundred forty million, two hundred fifty thousand, five hundred sixty-six".