218055385 has 4 divisors (see below), whose sum is σ = 261666468. Its totient is φ = 174444304.

The previous prime is 218055377. The next prime is 218055491. The reversal of 218055385 is 583550812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32114889 + 185940496 = 5667^2 + 13636^2 .

It is a cyclic number.

It is not a de Polignac number, because 218055385 - 2³ = 218055377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21805534 + ... + 21805543.

It is an arithmetic number, because the mean of its divisors is an integer number (65416617).

Almost surely, 2^218055385 is an apocalyptic number.

It is an amenable number.

218055385 is a deficient number, since it is larger than the sum of its proper divisors (43611083).

218055385 is an equidigital number, since it uses as much as digits as its factorization.

218055385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43611082.

The product of its (nonzero) digits is 48000, while the sum is 37.

The square root of 218055385 is about 14766.6985138859. The cubic root of 218055385 is about 601.8971294369.

The spelling of 218055385 in words is "two hundred eighteen million, fifty-five thousand, three hundred eighty-five".