638842635356 has 12 divisors (see below), whose sum is σ = 1120521254160. Its totient is φ = 318693705600.

The previous prime is 638842635341. The next prime is 638842635427. The reversal of 638842635356 is 653536248836.

It is a junction number, because it is equal to n+sod(n) for n = 638842635295 and 638842635304.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181901045 + ... + 181904556.

It is an arithmetic number, because the mean of its divisors is an integer number (93376771180).

Almost surely, 2^638842635356 is an apocalyptic number.

It is an amenable number.

638842635356 is a deficient number, since it is larger than the sum of its proper divisors (481678618804).

638842635356 is a wasteful number, since it uses less digits than its factorization.

638842635356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363806044 (or 363806042 counting only the distinct ones).

The product of its digits is 74649600, while the sum is 59.

The spelling of 638842635356 in words is "six hundred thirty-eight billion, eight hundred forty-two million, six hundred thirty-five thousand, three hundred fifty-six".