18944181 has 6 divisors (see below), whose sum is σ = 27363830. Its totient is φ = 12629448.

The previous prime is 18944147. The next prime is 18944201. The reversal of 18944181 is 18144981.

It can be written as a sum of positive squares in only one way, i.e., 12006225 + 6937956 = 3465^2 + 2634^2 .

It is not a de Polignac number, because 18944181 - 2⁶ = 18944117 is a prime.

It is a super-2 number, since 2×18944181² = 717763987521522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18944141) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1052446 + ... + 1052463.

Almost surely, 2^18944181 is an apocalyptic number.

It is an amenable number.

18944181 is a deficient number, since it is larger than the sum of its proper divisors (8419649).

18944181 is a wasteful number, since it uses less digits than its factorization.

18944181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2104915 (or 2104912 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 18944181 is about 4352.4913555342. The cubic root of 18944181 is about 266.5785971326.

The spelling of 18944181 in words is "eighteen million, nine hundred forty-four thousand, one hundred eighty-one".