638361568075660 has 384 divisors, whose sum is σ = 1689342816752640. Its totient is φ = 199137968640000.

The previous prime is 638361568075619. The next prime is 638361568075661. The reversal of 638361568075660 is 66570865163836.

It is a self number, because there is not a number n which added to its sum of digits gives 638361568075660.

It is not an unprimeable number, because it can be changed into a prime (638361568075661) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 27455219035 + ... + 27455242285.

It is an arithmetic number, because the mean of its divisors is an integer number (4399330251960).

Almost surely, 2^{638361568075660} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638361568075660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (844671408376320).

638361568075660 is an abundant number, since it is smaller than the sum of its proper divisors (1050981248676980).

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

638361568075660 is a wasteful number, since it uses less digits than its factorization.

638361568075660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32889 (or 32887 counting only the distinct ones).

The product of its (nonzero) digits is 783820800, while the sum is 70.

The spelling of 638361568075660 in words is "six hundred thirty-eight trillion, three hundred sixty-one billion, five hundred sixty-eight million, seventy-five thousand, six hundred sixty".