18424181 has 2 divisors, whose sum is σ = 18424182. Its totient is φ = 18424180.

The previous prime is 18424177. The next prime is 18424201. The reversal of 18424181 is 18142481.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14945956 + 3478225 = 3866^2 + 1865^2 .

It is a cyclic number.

It is not a de Polignac number, because 18424181 - 2² = 18424177 is a prime.

It is a super-2 number, since 2×18424181² = 678900891041522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is equal to p_1176671 and since 18424181 and 1176671 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18424111) 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, 9212090 + 9212091.

It is an arithmetic number, because the mean of its divisors is an integer number (9212091).

Almost surely, 2^18424181 is an apocalyptic number.

It is an amenable number.

18424181 is a deficient number, since it is larger than the sum of its proper divisors (1).

18424181 is an equidigital number, since it uses as much as digits as its factorization.

18424181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2048, while the sum is 29.

The square root of 18424181 is about 4292.3398048151. The cubic root of 18424181 is about 264.1168225321.

The spelling of 18424181 in words is "eighteen million, four hundred twenty-four thousand, one hundred eighty-one".