639403390 has 16 divisors (see below), whose sum is σ = 1211501520. Its totient is φ = 242300160.

The previous prime is 639403357. The next prime is 639403393. The reversal of 639403390 is 93304936.

639403390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639403393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1682451 + ... + 1682830.

It is an arithmetic number, because the mean of its divisors is an integer number (75718845).

Almost surely, 2^639403390 is an apocalyptic number.

639403390 is a deficient number, since it is larger than the sum of its proper divisors (572098130).

639403390 is a wasteful number, since it uses less digits than its factorization.

639403390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3365307.

The product of its (nonzero) digits is 52488, while the sum is 37.

The square root of 639403390 is about 25286.4269915700. The cubic root of 639403390 is about 861.5060099936.

The spelling of 639403390 in words is "six hundred thirty-nine million, four hundred three thousand, three hundred ninety".