638613621702 has 96 divisors (see below), whose sum is σ = 1625263091712. Its totient is φ = 177441181632.

The previous prime is 638613621691. The next prime is 638613621757. The reversal of 638613621702 is 207126316836.

638613621702 is a `hidden beast` number, since 6 + 3 + 8 + 6 + 13 + 621 + 7 + 0 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 586323 + ... + 1273185.

It is an arithmetic number, because the mean of its divisors is an integer number (16929823872).

Almost surely, 2^638613621702 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638613621702, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812631545856).

638613621702 is an abundant number, since it is smaller than the sum of its proper divisors (986649470010).

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

638613621702 is a wasteful number, since it uses less digits than its factorization.

638613621702 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687082 (or 687079 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 638613621702 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred twenty-one thousand, seven hundred two".