18181105 has 4 divisors (see below), whose sum is σ = 21817332. Its totient is φ = 14544880.

The previous prime is 18181103. The next prime is 18181117. The reversal of 18181105 is 50118181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50118181 = 19 ⋅2637799.

It can be written as a sum of positive squares in 2 ways, for example, as 3157729 + 15023376 = 1777^2 + 3876^2 .

It is not a de Polignac number, because 18181105 - 2¹ = 18181103 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18181105.

It is not an unprimeable number, because it can be changed into a prime (18181103) 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, 1818106 + ... + 1818115.

It is an arithmetic number, because the mean of its divisors is an integer number (5454333).

Almost surely, 2^18181105 is an apocalyptic number.

It is an amenable number.

18181105 is a deficient number, since it is larger than the sum of its proper divisors (3636227).

18181105 is an equidigital number, since it uses as much as digits as its factorization.

18181105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3636226.

The product of its (nonzero) digits is 320, while the sum is 25.

The square root of 18181105 is about 4263.9306983111. The cubic root of 18181105 is about 262.9501512698.

Adding to 18181105 its reverse (50118181), we get a palindrome (68299286).

The spelling of 18181105 in words is "eighteen million, one hundred eighty-one thousand, one hundred five".