638580085836 has 192 divisors, whose sum is σ = 1885159858176. Its totient is φ = 163415347200.

The previous prime is 638580085777. The next prime is 638580085849.

638580085836 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 638580085836.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 136650796 + ... + 136655468.

It is an arithmetic number, because the mean of its divisors is an integer number (9818540928).

Almost surely, 2^638580085836 is an apocalyptic number.

638580085836 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 638580085836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (942579929088).

638580085836 is an abundant number, since it is smaller than the sum of its proper divisors (1246579772340).

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

638580085836 is a wasteful number, since it uses less digits than its factorization.

638580085836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6852 (or 6850 counting only the distinct ones).

The product of its (nonzero) digits is 33177600, while the sum is 60.

The spelling of 638580085836 in words is "six hundred thirty-eight billion, five hundred eighty million, eighty-five thousand, eight hundred thirty-six".