639130638 has 8 divisors (see below), whose sum is σ = 1278261288. Its totient is φ = 213043544.

The previous prime is 639130631. The next prime is 639130643. The reversal of 639130638 is 836031936.

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

639130638 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 639130596 and 639130605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639130631) 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, 53260881 + ... + 53260892.

It is an arithmetic number, because the mean of its divisors is an integer number (159782661).

Almost surely, 2^639130638 is an apocalyptic number.

639130638 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.

639130638 is a wasteful number, since it uses less digits than its factorization.

639130638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106521778.

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 639130638 is about 25281.0331671789. The cubic root of 639130638 is about 861.3834942701.

The spelling of 639130638 in words is "six hundred thirty-nine million, one hundred thirty thousand, six hundred thirty-eight".