638941000 has 64 divisors (see below), whose sum is σ = 1543426560. Its totient is φ = 247320000.

The previous prime is 638940997. The next prime is 638941001. The reversal of 638941000 is 149836.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (638941001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20695 + ... + 41305.

It is an arithmetic number, because the mean of its divisors is an integer number (24116040).

Almost surely, 2^638941000 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 638941000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771713280).

638941000 is an abundant number, since it is smaller than the sum of its proper divisors (904485560).

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

638941000 is a wasteful number, since it uses less digits than its factorization.

638941000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20663 (or 20649 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 638941000 is about 25277.2822906261. The cubic root of 638941000 is about 861.2982914481.

The spelling of 638941000 in words is "six hundred thirty-eight million, nine hundred forty-one thousand".