638602602820 has 144 divisors (see below), whose sum is σ = 1687985345088. Its totient is φ = 201148496640.

The previous prime is 638602602797. The next prime is 638602602821. The reversal of 638602602820 is 28206206836.

638602602820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (638602602821) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2569359 + ... + 2806921.

It is an arithmetic number, because the mean of its divisors is an integer number (11722120452).

Almost surely, 2^638602602820 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 638602602820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (843992672544).

638602602820 is an abundant number, since it is smaller than the sum of its proper divisors (1049382742268).

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

638602602820 is a wasteful number, since it uses less digits than its factorization.

638602602820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237810 (or 237801 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 43.

The spelling of 638602602820 in words is "six hundred thirty-eight billion, six hundred two million, six hundred two thousand, eight hundred twenty".