11561181 has 4 divisors (see below), whose sum is σ = 15414912. Its totient is φ = 7707452.

The previous prime is 11561161. The next prime is 11561197. The reversal of 11561181 is 18116511.

It is a happy number.

11561181 is digitally balanced in base 2 and base 4, because in such bases 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 Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11561181 - 2⁶ = 11561117 is a prime.

It is a super-2 number, since 2×11561181² = 267321812229522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11561161) 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, 1926861 + ... + 1926866.

It is an arithmetic number, because the mean of its divisors is an integer number (3853728).

Almost surely, 2^11561181 is an apocalyptic number.

It is an amenable number.

11561181 is a deficient number, since it is larger than the sum of its proper divisors (3853731).

11561181 is an equidigital number, since it uses as much as digits as its factorization.

11561181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3853730.

The product of its digits is 240, while the sum is 24.

The square root of 11561181 is about 3400.1736720350. The cubic root of 11561181 is about 226.1174435921.

Adding to 11561181 its reverse (18116511), we get a palindrome (29677692).

The spelling of 11561181 in words is "eleven million, five hundred sixty-one thousand, one hundred eighty-one".