18458181 has 24 divisors (see below), whose sum is σ = 31524480. Its totient is φ = 10182816.

The previous prime is 18458149. The next prime is 18458189. The reversal of 18458181 is 18185481.

It is a happy number.

It is not a de Polignac number, because 18458181 - 2⁵ = 18458149 is a prime.

It is a super-2 number, since 2×18458181² = 681408891657522, which contains 22 as substring.

18458181 is a modest number, since divided by 8181 gives 1845 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18458189) 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 in 23 ways as a sum of consecutive naturals, for example, 3225 + ... + 6878.

It is an arithmetic number, because the mean of its divisors is an integer number (1313520).

Almost surely, 2^18458181 is an apocalyptic number.

It is an amenable number.

18458181 is a deficient number, since it is larger than the sum of its proper divisors (13066299).

18458181 is a wasteful number, since it uses less digits than its factorization.

18458181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10145 (or 10142 counting only the distinct ones).

The product of its digits is 10240, while the sum is 36.

The square root of 18458181 is about 4296.2985231476. The cubic root of 18458181 is about 264.2791898351.

The spelling of 18458181 in words is "eighteen million, four hundred fifty-eight thousand, one hundred eighty-one".