638932320 has 384 divisors, whose sum is σ = 2492743680. Its totient is φ = 151787520.

The previous prime is 638932309. The next prime is 638932409. The reversal of 638932320 is 23239836.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1740777 + ... + 1741143.

It is an arithmetic number, because the mean of its divisors is an integer number (6491520).

Almost surely, 2^638932320 is an apocalyptic number.

638932320 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 638932320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246371840).

638932320 is an abundant number, since it is smaller than the sum of its proper divisors (1853811360).

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

638932320 is a wasteful number, since it uses less digits than its factorization.

638932320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 638932320 is about 25277.1105943698. The cubic root of 638932320 is about 861.2943911908.

The spelling of 638932320 in words is "six hundred thirty-eight million, nine hundred thirty-two thousand, three hundred twenty".