638887680 has 216 divisors, whose sum is σ = 2283066240. Its totient is φ = 164782080.

The previous prime is 638887651. The next prime is 638887703. The reversal of 638887680 is 86788836.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 356226 + ... + 358014.

Almost surely, 2^638887680 is an apocalyptic number.

638887680 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 638887680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1141533120).

638887680 is an abundant number, since it is smaller than the sum of its proper divisors (1644178560).

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

638887680 is a wasteful number, since it uses less digits than its factorization.

638887680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1847 (or 1830 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The square root of 638887680 is about 25276.2275666287. The cubic root of 638887680 is about 861.2743321663.

The spelling of 638887680 in words is "six hundred thirty-eight million, eight hundred eighty-seven thousand, six hundred eighty".