218223385 has 4 divisors (see below), whose sum is σ = 261868068. Its totient is φ = 174578704.

The previous prime is 218223377. The next prime is 218223427. The reversal of 218223385 is 583322812.

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 57517056 + 160706329 = 7584^2 + 12677^2 .

It is a cyclic number.

It is not a de Polignac number, because 218223385 - 2³ = 218223377 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218223385.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21822334 + ... + 21822343.

It is an arithmetic number, because the mean of its divisors is an integer number (65467017).

Almost surely, 2^218223385 is an apocalyptic number.

It is an amenable number.

218223385 is a deficient number, since it is larger than the sum of its proper divisors (43644683).

218223385 is an equidigital number, since it uses as much as digits as its factorization.

218223385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43644682.

The product of its digits is 23040, while the sum is 34.

The square root of 218223385 is about 14772.3858939577. The cubic root of 218223385 is about 602.0516662610.

The spelling of 218223385 in words is "two hundred eighteen million, two hundred twenty-three thousand, three hundred eighty-five".