218388985920 has 840 divisors, whose sum is σ = 912693583296. Its totient is φ = 49420191744.

The previous prime is 218388985879. The next prime is 218388985957. The reversal of 218388985920 is 29589883812.

218388985920 is a `hidden beast` number, since 2 + 1 + 8 + 38 + 8 + 9 + 8 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (840).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 135897757 + ... + 135899363.

Almost surely, 2^218388985920 is an apocalyptic number.

218388985920 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 218388985920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (456346791648).

218388985920 is an abundant number, since it is smaller than the sum of its proper divisors (694304597376).

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

218388985920 is a wasteful number, since it uses less digits than its factorization.

218388985920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757 (or 1731 counting only the distinct ones).

The product of its (nonzero) digits is 19906560, while the sum is 63.

The spelling of 218388985920 in words is "two hundred eighteen billion, three hundred eighty-eight million, nine hundred eighty-five thousand, nine hundred twenty".