638596900 has 72 divisors (see below), whose sum is σ = 1443907584. Its totient is φ = 244876800.

The previous prime is 638596879. The next prime is 638596901. The reversal of 638596900 is 9695836.

It is a super-2 number, since 2×638596900² = 815612001379220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638596901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 349389 + ... + 351211.

It is an arithmetic number, because the mean of its divisors is an integer number (20054272).

Almost surely, 2^638596900 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 638596900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (721953792).

638596900 is an abundant number, since it is smaller than the sum of its proper divisors (805310684).

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

638596900 is a wasteful number, since it uses less digits than its factorization.

638596900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1981 (or 1974 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 46.

The square root of 638596900 is about 25270.4748669272. The cubic root of 638596900 is about 861.1436470383.

It can be divided in two parts, 6385 and 96900, that added together give a triangular number (103285 = T₄₅₄).

The spelling of 638596900 in words is "six hundred thirty-eight million, five hundred ninety-six thousand, nine hundred".