640438192 has 20 divisors (see below), whose sum is σ = 1241873640. Its totient is φ = 319954688.

The previous prime is 640438189. The next prime is 640438219. The reversal of 640438192 is 291834046.

It is a super-2 number, since 2×640438192² = 820322155544457728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4248 + ... + 36040.

It is an arithmetic number, because the mean of its divisors is an integer number (62093682).

Almost surely, 2^640438192 is an apocalyptic number.

It is an amenable number.

640438192 is a deficient number, since it is larger than the sum of its proper divisors (601435448).

640438192 is a wasteful number, since it uses less digits than its factorization.

640438192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33060 (or 33054 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 640438192 is about 25306.8803292701. The cubic root of 640438192 is about 861.9705094858.

The spelling of 640438192 in words is "six hundred forty million, four hundred thirty-eight thousand, one hundred ninety-two".