218142720 has 240 divisors, whose sum is σ = 784864080. Its totient is φ = 57950208.

The previous prime is 218142679. The next prime is 218142721. The reversal of 218142720 is 27241812.

218142720 is a `hidden beast` number, since 218 + 1 + 427 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218142721) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 829309 + ... + 829571.

It is an arithmetic number, because the mean of its divisors is an integer number (3270267).

Almost surely, 2^218142720 is an apocalyptic number.

218142720 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 218142720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392432040).

218142720 is an abundant number, since it is smaller than the sum of its proper divisors (566721360).

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

218142720 is an equidigital number, since it uses as much as digits as its factorization.

218142720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 218142720 is about 14769.6553785117. The cubic root of 218142720 is about 601.9774754912.

The spelling of 218142720 in words is "two hundred eighteen million, one hundred forty-two thousand, seven hundred twenty".