639822439 has 2 divisors, whose sum is σ = 639822440. Its totient is φ = 639822438.

The previous prime is 639822437. The next prime is 639822451. The reversal of 639822439 is 934228936.

639822439 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 is a cyclic number.

It is not a de Polignac number, because 639822439 - 2¹ = 639822437 is a prime.

Together with 639822437, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639822437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319911219 + 319911220.

It is an arithmetic number, because the mean of its divisors is an integer number (319911220).

Almost surely, 2^639822439 is an apocalyptic number.

639822439 is a deficient number, since it is larger than the sum of its proper divisors (1).

639822439 is an equidigital number, since it uses as much as digits as its factorization.

639822439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 46.

The square root of 639822439 is about 25294.7116805074. The cubic root of 639822439 is about 861.6941720626.

The spelling of 639822439 in words is "six hundred thirty-nine million, eight hundred twenty-two thousand, four hundred thirty-nine".