640020285064 has 16 divisors (see below), whose sum is σ = 1210657841820. Its totient is φ = 317178193920.

The previous prime is 640020285053. The next prime is 640020285067. The reversal of 640020285064 is 460582020046.

It can be written as a sum of positive squares in 2 ways, for example, as 403491744100 + 236528540964 = 635210^2 + 486342^2 .

It is not an unprimeable number, because it can be changed into a prime (640020285067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353992617 + ... + 353994424.

Almost surely, 2^640020285064 is an apocalyptic number.

It is an amenable number.

640020285064 is a deficient number, since it is larger than the sum of its proper divisors (570637556756).

640020285064 is a wasteful number, since it uses less digits than its factorization.

640020285064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707987160 (or 707987156 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 37.

The spelling of 640020285064 in words is "six hundred forty billion, twenty million, two hundred eighty-five thousand, sixty-four".