640488840 has 32 divisors (see below), whose sum is σ = 1921466880. Its totient is φ = 170796992.

The previous prime is 640488817. The next prime is 640488853. The reversal of 640488840 is 48884046.

640488840 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 640488792 and 640488801.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2668584 + ... + 2668823.

It is an arithmetic number, because the mean of its divisors is an integer number (60045840).

Almost surely, 2^640488840 is an apocalyptic number.

640488840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640488840 is an abundant number, since it is smaller than the sum of its proper divisors (1280978040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640488840 is a wasteful number, since it uses less digits than its factorization.

640488840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5337421 (or 5337417 counting only the distinct ones).

The product of its (nonzero) digits is 196608, while the sum is 42.

The square root of 640488840 is about 25307.8809859696. The cubic root of 640488840 is about 861.9932313930.

The spelling of 640488840 in words is "six hundred forty million, four hundred eighty-eight thousand, eight hundred forty".