638523900 has 162 divisors, whose sum is σ = 2328340560. Its totient is φ = 145938240.

The previous prime is 638523889. The next prime is 638523917. The reversal of 638523900 is 9325836.

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 53 ways as a sum of consecutive naturals, for example, 36861 + ... + 51339.

Almost surely, 2^638523900 is an apocalyptic number.

638523900 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 638523900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164170280).

638523900 is an abundant number, since it is smaller than the sum of its proper divisors (1689816660).

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

638523900 is a wasteful number, since it uses less digits than its factorization.

638523900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14513 (or 14496 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 638523900 is about 25269.0304523145. The cubic root of 638523900 is about 861.1108324507.

The spelling of 638523900 in words is "six hundred thirty-eight million, five hundred twenty-three thousand, nine hundred".