639308399 has 4 divisors (see below), whose sum is σ = 643907880. Its totient is φ = 634708920.

The previous prime is 639308389. The next prime is 639308431. The reversal of 639308399 is 993803936.

639308399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 639308399 - 2²⁰ = 638259823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639308389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2299532 + ... + 2299809.

It is an arithmetic number, because the mean of its divisors is an integer number (160976970).

Almost surely, 2^639308399 is an apocalyptic number.

639308399 is a deficient number, since it is larger than the sum of its proper divisors (4599481).

639308399 is a wasteful number, since it uses less digits than its factorization.

639308399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4599480.

The product of its (nonzero) digits is 944784, while the sum is 50.

The square root of 639308399 is about 25284.5486216385. The cubic root of 639308399 is about 861.4633455496.

The spelling of 639308399 in words is "six hundred thirty-nine million, three hundred eight thousand, three hundred ninety-nine".