18201181 has 2 divisors, whose sum is σ = 18201182. Its totient is φ = 18201180.

The previous prime is 18201121. The next prime is 18201193. The reversal of 18201181 is 18110281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13205956 + 4995225 = 3634^2 + 2235^2 .

It is a cyclic number.

It is not a de Polignac number, because 18201181 - 2⁹ = 18200669 is a prime.

It is a super-2 number, since 2×18201181² = 662565979589522, which contains 22 as substring.

It is equal to p_1163281 and since 18201181 and 1163281 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 (18201121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9100590 + 9100591.

It is an arithmetic number, because the mean of its divisors is an integer number (9100591).

Almost surely, 2^18201181 is an apocalyptic number.

It is an amenable number.

18201181 is a deficient number, since it is larger than the sum of its proper divisors (1).

18201181 is an equidigital number, since it uses as much as digits as its factorization.

18201181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 22.

The square root of 18201181 is about 4266.2842146299. The cubic root of 18201181 is about 263.0469008965.

The spelling of 18201181 in words is "eighteen million, two hundred one thousand, one hundred eighty-one".