11405881 has 4 divisors (see below), whose sum is σ = 11506932. Its totient is φ = 11304832.

The previous prime is 11405873. The next prime is 11405899. The reversal of 11405881 is 18850411.

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 614656 + 10791225 = 784^2 + 3285^2 .

It is a cyclic number.

It is not a de Polignac number, because 11405881 - 2³ = 11405873 is a prime.

It is a super-2 number, since 2×11405881² = 260188242772322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11405081) 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 3 ways as a sum of consecutive naturals, for example, 50356 + ... + 50581.

It is an arithmetic number, because the mean of its divisors is an integer number (2876733).

Almost surely, 2^11405881 is an apocalyptic number.

It is an amenable number.

11405881 is a deficient number, since it is larger than the sum of its proper divisors (101051).

11405881 is a wasteful number, since it uses less digits than its factorization.

11405881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101050.

The product of its (nonzero) digits is 1280, while the sum is 28.

The square root of 11405881 is about 3377.2593918738. The cubic root of 11405881 is about 225.1004062159.

It can be divided in two parts, 1140 and 5881, that added together give a triangular number (7021 = T₁₁₈).

The spelling of 11405881 in words is "eleven million, four hundred five thousand, eight hundred eighty-one".