638880000 has 360 divisors, whose sum is σ = 2337076896. Its totient is φ = 154880000.

The previous prime is 638879957. The next prime is 638880019. The reversal of 638880000 is 88836.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 1100 × 660 × 880.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 58079995 + ... + 58080005.

Almost surely, 2^638880000 is an apocalyptic number.

638880000 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 638880000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1168538448).

638880000 is an abundant number, since it is smaller than the sum of its proper divisors (1698196896).

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

638880000 is an frugal number, since it uses more digits than its factorization.

638880000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 638880000 is about 25276.0756447673. The cubic root of 638880000 is about 861.2708810571.

Multiplying 638880000 by its sum of digits (33), we get a square (21083040000 = 145200²).

638880000 divided by its sum of digits (33) gives a square (19360000 = 4400²).

The spelling of 638880000 in words is "six hundred thirty-eight million, eight hundred eighty thousand".