640520204 has 24 divisors (see below), whose sum is σ = 1152597600. Its totient is φ = 311265920.

The previous prime is 640520189. The next prime is 640520207. The reversal of 640520204 is 402025046.

It is a super-2 number, since 2×640520204² = 820532263464403232, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640520204.

It is not an unprimeable number, because it can be changed into a prime (640520207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36857 + ... + 51375.

It is an arithmetic number, because the mean of its divisors is an integer number (48024900).

Almost surely, 2^640520204 is an apocalyptic number.

It is an amenable number.

640520204 is a deficient number, since it is larger than the sum of its proper divisors (512077396).

640520204 is a wasteful number, since it uses less digits than its factorization.

640520204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14833 (or 14831 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 640520204 is about 25308.5006272596. The cubic root of 640520204 is about 862.0073014349.

The spelling of 640520204 in words is "six hundred forty million, five hundred twenty thousand, two hundred four".