638630400 has 120 divisors (see below), whose sum is σ = 2109802464. Its totient is φ = 170291200.

The previous prime is 638630393. The next prime is 638630417. The reversal of 638630400 is 4036836.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30085 + ... + 46715.

Almost surely, 2^638630400 is an apocalyptic number.

638630400 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 638630400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054901232).

638630400 is an abundant number, since it is smaller than the sum of its proper divisors (1471172064).

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

638630400 is a wasteful number, since it uses less digits than its factorization.

638630400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16662 (or 16641 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 638630400 is about 25271.1376870928. The cubic root of 638630400 is about 861.1587049503.

The spelling of 638630400 in words is "six hundred thirty-eight million, six hundred thirty thousand, four hundred".