18481181 has 4 divisors (see below), whose sum is σ = 18715200. Its totient is φ = 18247164.

The previous prime is 18481157. The next prime is 18481189. The reversal of 18481181 is 18118481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18481181 - 2¹⁸ = 18219037 is a prime.

It is a super-2 number, since 2×18481181² = 683108102309522, 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 (18481189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116891 + ... + 117048.

It is an arithmetic number, because the mean of its divisors is an integer number (4678800).

Almost surely, 2^18481181 is an apocalyptic number.

It is an amenable number.

18481181 is a deficient number, since it is larger than the sum of its proper divisors (234019).

18481181 is an equidigital number, since it uses as much as digits as its factorization.

18481181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234018.

The product of its digits is 2048, while the sum is 32.

The square root of 18481181 is about 4298.9744125780. The cubic root of 18481181 is about 264.3889135112.

The spelling of 18481181 in words is "eighteen million, four hundred eighty-one thousand, one hundred eighty-one".