2218166393 has 4 divisors (see below), whose sum is σ = 2248552308. Its totient is φ = 2187780480.

The previous prime is 2218166371. The next prime is 2218166399. The reversal of 2218166393 is 3936618122.

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 1186664704 + 1031501689 = 34448^2 + 32117^2 .

It is a cyclic number.

It is not a de Polignac number, because 2218166393 - 2⁶ = 2218166329 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 2218166393.

It is not an unprimeable number, because it can be changed into a prime (2218166399) 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 3 ways as a sum of consecutive naturals, for example, 15192848 + ... + 15192993.

It is an arithmetic number, because the mean of its divisors is an integer number (562138077).

Almost surely, 2^2218166393 is an apocalyptic number.

It is an amenable number.

2218166393 is a deficient number, since it is larger than the sum of its proper divisors (30385915).

2218166393 is an equidigital number, since it uses as much as digits as its factorization.

2218166393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30385914.

The product of its digits is 93312, while the sum is 41.

The square root of 2218166393 is about 47097.4138674301. The cubic root of 2218166393 is about 1304.1614951808.

The spelling of 2218166393 in words is "two billion, two hundred eighteen million, one hundred sixty-six thousand, three hundred ninety-three".