640661050 has 24 divisors (see below), whose sum is σ = 1192441536. Its totient is φ = 256089840.

The previous prime is 640661033. The next prime is 640661051. The reversal of 640661050 is 50166046.

It is not an unprimeable number, because it can be changed into a prime (640661051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89919 + ... + 96781.

It is an arithmetic number, because the mean of its divisors is an integer number (49685064).

Almost surely, 2^640661050 is an apocalyptic number.

640661050 is a deficient number, since it is larger than the sum of its proper divisors (551780486).

640661050 is a wasteful number, since it uses less digits than its factorization.

640661050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8742 (or 8737 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 640661050 is about 25311.2830571664. The cubic root of 640661050 is about 862.0704799688.

The spelling of 640661050 in words is "six hundred forty million, six hundred sixty-one thousand, fifty".