639303839 has 2 divisors, whose sum is σ = 639303840. Its totient is φ = 639303838.

The previous prime is 639303803. The next prime is 639303859. The reversal of 639303839 is 938303936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639303839 - 2²⁰ = 638255263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639303839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639303859) 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, 319651919 + 319651920.

It is an arithmetic number, because the mean of its divisors is an integer number (319651920).

Almost surely, 2^639303839 is an apocalyptic number.

639303839 is a deficient number, since it is larger than the sum of its proper divisors (1).

639303839 is an equidigital number, since it uses as much as digits as its factorization.

639303839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 314928, while the sum is 44.

The square root of 639303839 is about 25284.4584478292. The cubic root of 639303839 is about 861.4612973560.

The spelling of 639303839 in words is "six hundred thirty-nine million, three hundred three thousand, eight hundred thirty-nine".