638205009120 has 384 divisors, whose sum is σ = 2640851942400. Its totient is φ = 140845049856.

The previous prime is 638205009119. The next prime is 638205009157. The reversal of 638205009120 is 21900502836.

638205009120 is a `hidden beast` number, since 6 + 3 + 8 + 20 + 500 + 9 + 120 = 666.

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, 513087 + ... + 1240833.

It is an arithmetic number, because the mean of its divisors is an integer number (6877218600).

Almost surely, 2^638205009120 is an apocalyptic number.

638205009120 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 638205009120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1320425971200).

638205009120 is an abundant number, since it is smaller than the sum of its proper divisors (2002646933280).

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

638205009120 is a wasteful number, since it uses less digits than its factorization.

638205009120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727807 (or 727793 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 638205009120 in words is "six hundred thirty-eight billion, two hundred five million, nine thousand, one hundred twenty".