638910000 has 300 divisors, whose sum is σ = 2316508480. Its totient is φ = 164160000.

The previous prime is 638909989. The next prime is 638910001. The reversal of 638910000 is 19836.

It is a tau number, because it is divible by the number of its divisors (300).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (638910001) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2789886 + ... + 2790114.

Almost surely, 2^638910000 is an apocalyptic number.

638910000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638910000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1158254240).

638910000 is an abundant number, since it is smaller than the sum of its proper divisors (1677598480).

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

638910000 is a wasteful number, since it uses less digits than its factorization.

638910000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 638910000 is about 25276.6690843552. The cubic root of 638910000 is about 861.2843617953.

Adding to 638910000 its reverse (19836), we get a palindrome (638929836).

The spelling of 638910000 in words is "six hundred thirty-eight million, nine hundred ten thousand".