639090402 has 8 divisors (see below), whose sum is σ = 1278180816. Its totient is φ = 213030132.

The previous prime is 639090391. The next prime is 639090407. The reversal of 639090402 is 204090936.

It is a sphenic number, since it is the product of 3 distinct primes.

639090402 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (639090407) 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, 53257528 + ... + 53257539.

It is an arithmetic number, because the mean of its divisors is an integer number (159772602).

Almost surely, 2^639090402 is an apocalyptic number.

639090402 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639090402 is a wasteful number, since it uses less digits than its factorization.

639090402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106515072.

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 639090402 is about 25280.2373802146. The cubic root of 639090402 is about 861.3654179689.

The spelling of 639090402 in words is "six hundred thirty-nine million, ninety thousand, four hundred two".