640126928 has 40 divisors (see below), whose sum is σ = 1422117312. Its totient is φ = 273431808.

The previous prime is 640126909. The next prime is 640126969. The reversal of 640126928 is 829621046.

640126928 is digitally balanced in base 2, 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 = 640126891 and 640126900.

It is a congruent number.

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, 25076 + ... + 43692.

Almost surely, 2^640126928 is an apocalyptic number.

It is an amenable number.

640126928 is an abundant number, since it is smaller than the sum of its proper divisors (781990384).

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

640126928 is a wasteful number, since it uses less digits than its factorization.

640126928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18939 (or 18933 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 640126928 is about 25300.7297918459. The cubic root of 640126928 is about 861.8308426816.

The spelling of 640126928 in words is "six hundred forty million, one hundred twenty-six thousand, nine hundred twenty-eight".