640068068 has 24 divisors (see below), whose sum is σ = 1144378368. Its totient is φ = 313136096.

The previous prime is 640068017. The next prime is 640068073. The reversal of 640068068 is 860860046.

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, 77255 + ... + 85137.

It is an arithmetic number, because the mean of its divisors is an integer number (47682432).

Almost surely, 2^640068068 is an apocalyptic number.

It is an amenable number.

640068068 is a deficient number, since it is larger than the sum of its proper divisors (504310300).

640068068 is a wasteful number, since it uses less digits than its factorization.

640068068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8323 (or 8321 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 640068068 is about 25299.5665575519. The cubic root of 640068068 is about 861.8044266090.

The spelling of 640068068 in words is "six hundred forty million, sixty-eight thousand, sixty-eight".