18194881 has 2 divisors, whose sum is σ = 18194882. Its totient is φ = 18194880.

The previous prime is 18194873. The next prime is 18194903. The reversal of 18194881 is 18849181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14508481 + 3686400 = 3809^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 18194881 - 2³ = 18194873 is a prime.

It is a super-2 number, since 2×18194881² = 662107389208322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18194821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9097440 + 9097441.

It is an arithmetic number, because the mean of its divisors is an integer number (9097441).

Almost surely, 2^18194881 is an apocalyptic number.

It is an amenable number.

18194881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18194881 is an equidigital number, since it uses as much as digits as its factorization.

18194881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 40.

The square root of 18194881 is about 4265.5458032941. The cubic root of 18194881 is about 263.0165477981.

The spelling of 18194881 in words is "eighteen million, one hundred ninety-four thousand, eight hundred eighty-one".