12090905 has 4 divisors (see below), whose sum is σ = 14509092. Its totient is φ = 9672720.

The previous prime is 12090889. The next prime is 12090931. The reversal of 12090905 is 50909021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50909021 = 1811 ⋅28111.

It can be written as a sum of positive squares in 2 ways, for example, as 7912969 + 4177936 = 2813^2 + 2044^2 .

It is not a de Polignac number, because 12090905 - 2⁴ = 12090889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1209086 + ... + 1209095.

It is an arithmetic number, because the mean of its divisors is an integer number (3627273).

Almost surely, 2^12090905 is an apocalyptic number.

It is an amenable number.

12090905 is a deficient number, since it is larger than the sum of its proper divisors (2418187).

12090905 is an equidigital number, since it uses as much as digits as its factorization.

12090905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2418186.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 12090905 is about 3477.1978660985. The cubic root of 12090905 is about 229.5195072993.

Adding to 12090905 its reverse (50909021), we get a palindrome (62999926).

The spelling of 12090905 in words is "twelve million, ninety thousand, nine hundred five".