638016400 has 120 divisors (see below), whose sum is σ = 1762458624. Its totient is φ = 217420800.

The previous prime is 638016397. The next prime is 638016427. The reversal of 638016400 is 4610836.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 534204 + ... + 535396.

Almost surely, 2^638016400 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 638016400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (881229312).

638016400 is an abundant number, since it is smaller than the sum of its proper divisors (1124442224).

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

638016400 is a wasteful number, since it uses less digits than its factorization.

638016400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409 (or 1398 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 638016400 is about 25258.9865196528. The cubic root of 638016400 is about 860.8826344780.

The spelling of 638016400 in words is "six hundred thirty-eight million, sixteen thousand, four hundred".