638801831256 has 32 divisors (see below), whose sum is σ = 1597034408640. Its totient is φ = 212929966368.

The previous prime is 638801831251. The next prime is 638801831279. The reversal of 638801831256 is 652138108836.

It is a happy number.

638801831256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×638801831256³ (a number of 36 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 638801831199 and 638801831208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638801831251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1246575 + ... + 1682721.

It is an arithmetic number, because the mean of its divisors is an integer number (49907325270).

Almost surely, 2^638801831256 is an apocalyptic number.

It is an amenable number.

638801831256 is an abundant number, since it is smaller than the sum of its proper divisors (958232577384).

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

638801831256 is a wasteful number, since it uses less digits than its factorization.

638801831256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497183 (or 497179 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 51.

The spelling of 638801831256 in words is "six hundred thirty-eight billion, eight hundred one million, eight hundred thirty-one thousand, two hundred fifty-six".