18322181 has 2 divisors, whose sum is σ = 18322182. Its totient is φ = 18322180.

The previous prime is 18322123. The next prime is 18322193. The reversal of 18322181 is 18122381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18105025 + 217156 = 4255^2 + 466^2 .

It is a cyclic number.

It is not a de Polignac number, because 18322181 - 2²² = 14127877 is a prime.

It is a super-2 number, since 2×18322181² = 671404633193522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18322181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18327181) by changing a digit.

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 as a sum of consecutive naturals, namely, 9161090 + 9161091.

It is an arithmetic number, because the mean of its divisors is an integer number (9161091).

Almost surely, 2^18322181 is an apocalyptic number.

It is an amenable number.

18322181 is a deficient number, since it is larger than the sum of its proper divisors (1).

18322181 is an equidigital number, since it uses as much as digits as its factorization.

18322181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 26.

The square root of 18322181 is about 4280.4416828173. The cubic root of 18322181 is about 263.6285188852.

The spelling of 18322181 in words is "eighteen million, three hundred twenty-two thousand, one hundred eighty-one".