218422840 has 32 divisors (see below), whose sum is σ = 504737280. Its totient is φ = 85007232.

The previous prime is 218422819. The next prime is 218422847. The reversal of 218422840 is 48224812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218422847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72312 + ... + 75271.

It is an arithmetic number, because the mean of its divisors is an integer number (15773040).

Almost surely, 2^218422840 is an apocalyptic number.

218422840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218422840 is an abundant number, since it is smaller than the sum of its proper divisors (286314440).

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

218422840 is a wasteful number, since it uses less digits than its factorization.

218422840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147631 (or 147627 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 31.

The square root of 218422840 is about 14779.1352927023. The cubic root of 218422840 is about 602.2350344013.

The spelling of 218422840 in words is "two hundred eighteen million, four hundred twenty-two thousand, eight hundred forty".