639030942 has 72 divisors (see below), whose sum is σ = 1579222008. Its totient is φ = 185196000.

The previous prime is 639030923. The next prime is 639030983. The reversal of 639030942 is 249030936.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 639030897 and 639030906.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 101692 + ... + 107792.

It is an arithmetic number, because the mean of its divisors is an integer number (21933639).

Almost surely, 2^639030942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639030942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (789611004).

639030942 is an abundant number, since it is smaller than the sum of its proper divisors (940191066).

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

639030942 is a wasteful number, since it uses less digits than its factorization.

639030942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6166 (or 6140 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The square root of 639030942 is about 25279.0613354215. The cubic root of 639030942 is about 861.3387037639.

The spelling of 639030942 in words is "six hundred thirty-nine million, thirty thousand, nine hundred forty-two".