638658846 has 72 divisors (see below), whose sum is σ = 1614965040. Its totient is φ = 181875456.

The previous prime is 638658751. The next prime is 638658899. The reversal of 638658846 is 648856836.

It is a junction number, because it is equal to n+sod(n) for n = 638658792 and 638658801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 315630 + ... + 317646.

It is an arithmetic number, because the mean of its divisors is an integer number (22430070).

Almost surely, 2^638658846 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638658846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (807482520).

638658846 is an abundant number, since it is smaller than the sum of its proper divisors (976306194).

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

638658846 is a wasteful number, since it uses less digits than its factorization.

638658846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2398 (or 2388 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 54.

The square root of 638658846 is about 25271.7004968008. The cubic root of 638658846 is about 861.1714907268.

The spelling of 638658846 in words is "six hundred thirty-eight million, six hundred fifty-eight thousand, eight hundred forty-six".