638659637922 has 8 divisors (see below), whose sum is σ = 1277319275856. Its totient is φ = 212886545972.

The previous prime is 638659637911. The next prime is 638659637923. The reversal of 638659637922 is 229736956836.

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

638659637922 is an admirable number.

It is a super-2 number, since 2×638659637922² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638659637923) 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 3 ways as a sum of consecutive naturals, for example, 53221636488 + ... + 53221636499.

It is an arithmetic number, because the mean of its divisors is an integer number (159664909482).

Almost surely, 2^638659637922 is an apocalyptic number.

638659637922 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.

638659637922 is a wasteful number, since it uses less digits than its factorization.

638659637922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106443272992.

The product of its digits is 176359680, while the sum is 66.

The spelling of 638659637922 in words is "six hundred thirty-eight billion, six hundred fifty-nine million, six hundred thirty-seven thousand, nine hundred twenty-two".