638338880 has 56 divisors (see below), whose sum is σ = 1534073640. Its totient is φ = 252979200.

The previous prime is 638338879. The next prime is 638338889. The reversal of 638338880 is 88833836.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4910656 + 633428224 = 2216^2 + 25168^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638338889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25730 + ... + 44030.

Almost surely, 2^638338880 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 638338880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (767036820).

638338880 is an abundant number, since it is smaller than the sum of its proper divisors (895734760).

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

638338880 is a wasteful number, since it uses less digits than its factorization.

638338880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18427 (or 18417 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 47.

The square root of 638338880 is about 25265.3691839245. The cubic root of 638338880 is about 861.0276520000.

The spelling of 638338880 in words is "six hundred thirty-eight million, three hundred thirty-eight thousand, eight hundred eighty".