640520032 has 12 divisors (see below), whose sum is σ = 1261023876. Its totient is φ = 320260000.

The previous prime is 640520021. The next prime is 640520053. The reversal of 640520032 is 230025046.

It is a happy number.

It is a super-2 number, since 2×640520032² = 820531822786562048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 640519985 and 640520012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10008094 + ... + 10008157.

It is an arithmetic number, because the mean of its divisors is an integer number (105085323).

Almost surely, 2^640520032 is an apocalyptic number.

It is an amenable number.

640520032 is a deficient number, since it is larger than the sum of its proper divisors (620503844).

640520032 is a wasteful number, since it uses less digits than its factorization.

640520032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20016261 (or 20016253 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 640520032 is about 25308.4972291916. The cubic root of 640520032 is about 862.0072242761.

Adding to 640520032 its reverse (230025046), we get a palindrome (870545078).

The spelling of 640520032 in words is "six hundred forty million, five hundred twenty thousand, thirty-two".