638847291020 has 24 divisors (see below), whose sum is σ = 1342809035568. Its totient is φ = 255304683200.

The previous prime is 638847291001. The next prime is 638847291023. The reversal of 638847291020 is 20192748836.

It is a super-2 number, since 2×638847291020² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 638847291020.

It is not an unprimeable number, because it can be changed into a prime (638847291023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14617211 + ... + 14660850.

It is an arithmetic number, because the mean of its divisors is an integer number (55950376482).

Almost surely, 2^638847291020 is an apocalyptic number.

It is an amenable number.

638847291020 is an abundant number, since it is smaller than the sum of its proper divisors (703961744548).

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

638847291020 is a wasteful number, since it uses less digits than its factorization.

638847291020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29279161 (or 29279159 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 50.

The spelling of 638847291020 in words is "six hundred thirty-eight billion, eight hundred forty-seven million, two hundred ninety-one thousand, twenty".