640328415989 has 2 divisors, whose sum is σ = 640328415990. Its totient is φ = 640328415988.

The previous prime is 640328415971. The next prime is 640328416027. The reversal of 640328415989 is 989514823046.

It is a happy number.

640328415989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 526833543889 + 113494872100 = 725833^2 + 336890^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640328415989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640328415929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320164207994 + 320164207995.

It is an arithmetic number, because the mean of its divisors is an integer number (320164207995).

Almost surely, 2^640328415989 is an apocalyptic number.

It is an amenable number.

640328415989 is a deficient number, since it is larger than the sum of its proper divisors (1).

640328415989 is an equidigital number, since it uses as much as digits as its factorization.

640328415989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14929920, while the sum is 59.

The spelling of 640328415989 in words is "six hundred forty billion, three hundred twenty-eight million, four hundred fifteen thousand, nine hundred eighty-nine".