639384378 has 8 divisors (see below), whose sum is σ = 1278768768. Its totient is φ = 213128124.

The previous prime is 639384377. The next prime is 639384379. The reversal of 639384378 is 873483936.

639384378 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (639384377) and next prime (639384379).

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

639384378 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 639384378.

It is not an unprimeable number, because it can be changed into a prime (639384377) 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, 53282026 + ... + 53282037.

It is an arithmetic number, because the mean of its divisors is an integer number (159846096).

Almost surely, 2^639384378 is an apocalyptic number.

639384378 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.

639384378 is a wasteful number, since it uses less digits than its factorization.

639384378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106564068.

The product of its digits is 2612736, while the sum is 51.

The square root of 639384378 is about 25286.0510558687. The cubic root of 639384378 is about 861.4974712449.

The spelling of 639384378 in words is "six hundred thirty-nine million, three hundred eighty-four thousand, three hundred seventy-eight".