639919013 has 2 divisors, whose sum is σ = 639919014. Its totient is φ = 639919012.

The previous prime is 639919003. The next prime is 639919037. The reversal of 639919013 is 310919936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 557054404 + 82864609 = 23602^2 + 9103^2 .

It is a cyclic number.

It is not a de Polignac number, because 639919013 - 2⁴ = 639918997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639919003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319959506 + 319959507.

It is an arithmetic number, because the mean of its divisors is an integer number (319959507).

Almost surely, 2^639919013 is an apocalyptic number.

It is an amenable number.

639919013 is a deficient number, since it is larger than the sum of its proper divisors (1).

639919013 is an equidigital number, since it uses as much as digits as its factorization.

639919013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 639919013 is about 25296.6205845761. The cubic root of 639919013 is about 861.7375242289.

The spelling of 639919013 in words is "six hundred thirty-nine million, nine hundred nineteen thousand, thirteen".