216600638400 has 504 divisors, whose sum is σ = 830176292400. Its totient is φ = 53382758400.

The previous prime is 216600638393. The next prime is 216600638411. The reversal of 216600638400 is 4836006612.

216600638400 is a `hidden beast` number, since 2 + 1 + 6 + 600 + 6 + 3 + 8 + 40 + 0 = 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 71 ways as a sum of consecutive naturals, for example, 11207946 + ... + 11227254.

Almost surely, 2^216600638400 is an apocalyptic number.

216600638400 is a gapful number since it is divisible by the number (20) 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 216600638400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (415088146200).

216600638400 is an abundant number, since it is smaller than the sum of its proper divisors (613575654000).

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

216600638400 is a wasteful number, since it uses less digits than its factorization.

216600638400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19397 (or 19379 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The spelling of 216600638400 in words is "two hundred sixteen billion, six hundred million, six hundred thirty-eight thousand, four hundred".