18103905 has 20 divisors (see below), whose sum is σ = 32453652. Its totient is φ = 9655200.

The previous prime is 18103879. The next prime is 18103909. The reversal of 18103905 is 50930181.

It can be written as a sum of positive squares in 2 ways, for example, as 1846881 + 16257024 = 1359^2 + 4032^2 .

It is not a de Polignac number, because 18103905 - 2¹⁷ = 17972833 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18103909) 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 19 ways as a sum of consecutive naturals, for example, 21946 + ... + 22755.

Almost surely, 2^18103905 is an apocalyptic number.

18103905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18103905 is a deficient number, since it is larger than the sum of its proper divisors (14349747).

18103905 is an equidigital number, since it uses as much as digits as its factorization.

18103905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44718 (or 44709 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 18103905 is about 4254.8683880938. The cubic root of 18103905 is about 262.5774465361.

The spelling of 18103905 in words is "eighteen million, one hundred three thousand, nine hundred five".