640928063 has 2 divisors, whose sum is σ = 640928064. Its totient is φ = 640928062.

The previous prime is 640928053. The next prime is 640928089. The reversal of 640928063 is 360829046.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640928063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640928003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320464031 + 320464032.

It is an arithmetic number, because the mean of its divisors is an integer number (320464032).

Almost surely, 2^640928063 is an apocalyptic number.

640928063 is a deficient number, since it is larger than the sum of its proper divisors (1).

640928063 is an equidigital number, since it uses as much as digits as its factorization.

640928063 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 640928063 is about 25316.5570921482. The cubic root of 640928063 is about 862.1902271445.

The spelling of 640928063 in words is "six hundred forty million, nine hundred twenty-eight thousand, sixty-three".