639121370202 has 96 divisors (see below), whose sum is σ = 1681406064000. Its totient is φ = 171544189824.

The previous prime is 639121370201. The next prime is 639121370219. The reversal of 639121370202 is 202073121936.

639121370202 is a `hidden beast` number, since 63 + 9 + 1 + 21 + 370 + 202 = 666.

It is a super-2 number, since 2×639121370202² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639121370201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2228452 + ... + 2498847.

It is an arithmetic number, because the mean of its divisors is an integer number (17514646500).

Almost surely, 2^639121370202 is an apocalyptic number.

639121370202 is an abundant number, since it is smaller than the sum of its proper divisors (1042284693798).

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

639121370202 is a wasteful number, since it uses less digits than its factorization.

639121370202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4727380 (or 4727377 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The spelling of 639121370202 in words is "six hundred thirty-nine billion, one hundred twenty-one million, three hundred seventy thousand, two hundred two".