218509873920 has 864 divisors, whose sum is σ = 878400169920. Its totient is φ = 49686773760.

The previous prime is 218509873919. The next prime is 218509873957. The reversal of 218509873920 is 29378905812.

218509873920 is a `hidden beast` number, since 2 + 1 + 8 + 509 + 87 + 39 + 20 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 116662104 + ... + 116663976.

Almost surely, 2^218509873920 is an apocalyptic number.

218509873920 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 218509873920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (439200084960).

218509873920 is an abundant number, since it is smaller than the sum of its proper divisors (659890296000).

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

218509873920 is a wasteful number, since it uses less digits than its factorization.

218509873920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1973 (or 1956 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 218509873920 in words is "two hundred eighteen billion, five hundred nine million, eight hundred seventy-three thousand, nine hundred twenty".