639384052842 has 24 divisors (see below), whose sum is σ = 1436640712416. Its totient is φ = 213128017452.

The previous prime is 639384052831. The next prime is 639384052889. The reversal of 639384052842 is 248250483936.

639384052842 is a `hidden beast` number, since 6 + 3 + 9 + 38 + 40 + 528 + 42 = 666.

It is a super-2 number, since 2×639384052842² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 657802038 + ... + 657803009.

It is an arithmetic number, because the mean of its divisors is an integer number (59860029684).

Almost surely, 2^639384052842 is an apocalyptic number.

639384052842 is an abundant number, since it is smaller than the sum of its proper divisors (797256659574).

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

639384052842 is a wasteful number, since it uses less digits than its factorization.

639384052842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315605064 (or 1315605052 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 54.

The spelling of 639384052842 in words is "six hundred thirty-nine billion, three hundred eighty-four million, fifty-two thousand, eight hundred forty-two".