640848688 has 20 divisors (see below), whose sum is σ = 1244486320. Its totient is φ = 319690944.

The previous prime is 640848679. The next prime is 640848697. The reversal of 640848688 is 886848046.

It is an interprime number because it is at equal distance from previous prime (640848679) and next prime (640848697).

It is a super-2 number, since 2×640848688² = 821374081822642688, 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, 38595 + ... + 52642.

It is an arithmetic number, because the mean of its divisors is an integer number (62224316).

Almost surely, 2^640848688 is an apocalyptic number.

It is an amenable number.

640848688 is a deficient number, since it is larger than the sum of its proper divisors (603637632).

640848688 is a wasteful number, since it uses less digits than its factorization.

640848688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91684 (or 91678 counting only the distinct ones).

The product of its (nonzero) digits is 2359296, while the sum is 52.

The square root of 640848688 is about 25314.9893936379. The cubic root of 640848688 is about 862.1546333556.

The spelling of 640848688 in words is "six hundred forty million, eight hundred forty-eight thousand, six hundred eighty-eight".