640654064 has 20 divisors (see below), whose sum is σ = 1246694760. Its totient is φ = 318926400.

The previous prime is 640654019. The next prime is 640654093. The reversal of 640654064 is 460456046.

It is a congruent number.

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, 83762 + ... + 91089.

It is an arithmetic number, because the mean of its divisors is an integer number (62334738).

Almost surely, 2^640654064 is an apocalyptic number.

It is an amenable number.

640654064 is a deficient number, since it is larger than the sum of its proper divisors (606040696).

640654064 is a wasteful number, since it uses less digits than its factorization.

640654064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175088 (or 175082 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 35.

The square root of 640654064 is about 25311.1450550938. The cubic root of 640654064 is about 862.0673465146.

The spelling of 640654064 in words is "six hundred forty million, six hundred fifty-four thousand, sixty-four".