11905 has 4 divisors (see below), whose sum is σ = 14292. Its totient is φ = 9520.

The previous prime is 11903. The next prime is 11909. The reversal of 11905 is 50911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1296 + 10609 = 36^2 + 103^2 .

It is not a de Polignac number, because 11905 - 2¹ = 11903 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (11903) 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, 1186 + ... + 1195.

It is an arithmetic number, because the mean of its divisors is an integer number (3573).

It is a Proth number, since it is equal to 93 ⋅ 2⁷ + 1 and 93 < 2⁷.

2¹¹⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

11905 is a deficient number, since it is larger than the sum of its proper divisors (2387).

11905 is an equidigital number, since it uses as much as digits as its factorization.

11905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2386.

The product of its (nonzero) digits is 45, while the sum is 16.

The square root of 11905 is about 109.1100362020. The cubic root of 11905 is about 22.8337092425.

The spelling of 11905 in words is "eleven thousand, nine hundred five".