639343339 has 4 divisors (see below), whose sum is σ = 639557856. Its totient is φ = 639128824.

The previous prime is 639343333. The next prime is 639343373. The reversal of 639343339 is 933343936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 639343339 - 2²⁵ = 605788907 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639343295 and 639343304.

It is not an unprimeable number, because it can be changed into a prime (639343333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102724 + ... + 108769.

It is an arithmetic number, because the mean of its divisors is an integer number (159889464).

Almost surely, 2^639343339 is an apocalyptic number.

639343339 is a deficient number, since it is larger than the sum of its proper divisors (214517).

639343339 is a wasteful number, since it uses less digits than its factorization.

639343339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214516.

The product of its digits is 472392, while the sum is 43.

The square root of 639343339 is about 25285.2395480051. The cubic root of 639343339 is about 861.4790390610.

The spelling of 639343339 in words is "six hundred thirty-nine million, three hundred forty-three thousand, three hundred thirty-nine".