168221218 has 24 divisors (see below), whose sum is σ = 289425024. Its totient is φ = 73137240.

The previous prime is 168221197. The next prime is 168221281. The reversal of 168221218 is 812122861.

It is a self number, because there is not a number n which added to its sum of digits gives 168221218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9546 + ... + 20677.

It is an arithmetic number, because the mean of its divisors is an integer number (12059376).

Almost surely, 2^168221218 is an apocalyptic number.

168221218 is a deficient number, since it is larger than the sum of its proper divisors (121203806).

168221218 is a wasteful number, since it uses less digits than its factorization.

168221218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30270 (or 30259 counting only the distinct ones).

The product of its digits is 3072, while the sum is 31.

The square root of 168221218 is about 12970.0122590536. The cubic root of 168221218 is about 552.0269209898.

It can be divided in two parts, 1682 and 21218, that multiplied together give a square (35688676 = 5974²).

The spelling of 168221218 in words is "one hundred sixty-eight million, two hundred twenty-one thousand, two hundred eighteen".