11181281 has 4 divisors (see below), whose sum is σ = 11187972. Its totient is φ = 11174592.

The previous prime is 11181277. The next prime is 11181283. The reversal of 11181281 is 18218111.

11181281 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, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6838225 + 4343056 = 2615^2 + 2084^2 .

It is a cyclic number.

It is not a de Polignac number, because 11181281 - 2² = 11181277 is a prime.

It is a super-2 number, since 2×11181281² = 250042089601922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11181283) 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, 1541 + ... + 4973.

It is an arithmetic number, because the mean of its divisors is an integer number (2796993).

Almost surely, 2^11181281 is an apocalyptic number.

It is an amenable number.

11181281 is a deficient number, since it is larger than the sum of its proper divisors (6691).

11181281 is an equidigital number, since it uses as much as digits as its factorization.

11181281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6690.

The product of its digits is 128, while the sum is 23.

The square root of 11181281 is about 3343.8422510639. The cubic root of 11181281 is about 223.6130716573.

Adding to 11181281 its reverse (18218111), we get a palindrome (29399392).

The spelling of 11181281 in words is "eleven million, one hundred eighty-one thousand, two hundred eighty-one".