11561121 has 36 divisors (see below), whose sum is σ = 19755216. Its totient is φ = 6458400.

The previous prime is 11561117. The next prime is 11561159. The reversal of 11561121 is 12116511.

It is a happy number.

It is not a de Polignac number, because 11561121 - 2² = 11561117 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11561094 and 11561103.

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 35 ways as a sum of consecutive naturals, for example, 16386 + ... + 17076.

It is an arithmetic number, because the mean of its divisors is an integer number (548756).

Almost surely, 2^11561121 is an apocalyptic number.

11561121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11561121 is a deficient number, since it is larger than the sum of its proper divisors (8194095).

11561121 is a wasteful number, since it uses less digits than its factorization.

11561121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734 (or 718 counting only the distinct ones).

The product of its digits is 60, while the sum is 18.

The square root of 11561121 is about 3400.1648489448. The cubic root of 11561121 is about 226.1170524247.

Adding to 11561121 its reverse (12116511), we get a palindrome (23677632).

The spelling of 11561121 in words is "eleven million, five hundred sixty-one thousand, one hundred twenty-one".