638583385836 has 96 divisors (see below), whose sum is σ = 1669942552320. Its totient is φ = 188220844800.

The previous prime is 638583385823. The next prime is 638583385861.

638583385836 is nontrivially palindromic in base 10.

638583385836 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16923751 + ... + 16961441.

It is an arithmetic number, because the mean of its divisors is an integer number (17395234920).

Almost surely, 2^638583385836 is an apocalyptic number.

638583385836 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638583385836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834971276160).

638583385836 is an abundant number, since it is smaller than the sum of its proper divisors (1031359166484).

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

638583385836 is a wasteful number, since it uses less digits than its factorization.

638583385836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41215 (or 41213 counting only the distinct ones).

The product of its digits is 298598400, while the sum is 66.

The spelling of 638583385836 in words is "six hundred thirty-eight billion, five hundred eighty-three million, three hundred eighty-five thousand, eight hundred thirty-six".