11405 has 4 divisors (see below), whose sum is σ = 13692. Its totient is φ = 9120.

The previous prime is 11399. The next prime is 11411. The reversal of 11405 is 50411.

11405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (11399) and next prime (11411).

It can be written as a sum of positive squares in 2 ways, for example, as 5476 + 5929 = 74^2 + 77^2 .

It is not a de Polignac number, because 11405 - 2⁸ = 11149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 6.

It is a nialpdrome in base 5.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1136 + ... + 1145.

It is an arithmetic number, because the mean of its divisors is an integer number (3423).

2¹¹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

11405 is a deficient number, since it is larger than the sum of its proper divisors (2287).

11405 is an equidigital number, since it uses as much as digits as its factorization.

11405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2286.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 11405 is about 106.7941945988. The cubic root of 11405 is about 22.5094610417.

Adding to 11405 its reverse (50411), we get a palindrome (61816).

The spelling of 11405 in words is "eleven thousand, four hundred five".