639600839 has 2 divisors, whose sum is σ = 639600840. Its totient is φ = 639600838.

The previous prime is 639600821. The next prime is 639600847. The reversal of 639600839 is 938006936.

639600839 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639600839 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639600839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639600139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319800419 + 319800420.

It is an arithmetic number, because the mean of its divisors is an integer number (319800420).

Almost surely, 2^639600839 is an apocalyptic number.

639600839 is a deficient number, since it is larger than the sum of its proper divisors (1).

639600839 is an equidigital number, since it uses as much as digits as its factorization.

639600839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 44.

The square root of 639600839 is about 25290.3309389181. The cubic root of 639600839 is about 861.5946791063.

The spelling of 639600839 in words is "six hundred thirty-nine million, six hundred thousand, eight hundred thirty-nine".