11561221 has 8 divisors (see below), whose sum is σ = 13535424. Its totient is φ = 9667680.

The previous prime is 11561219. The next prime is 11561237. The reversal of 11561221 is 12216511.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11561221 - 2¹ = 11561219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11561021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19855 + ... + 20428.

It is an arithmetic number, because the mean of its divisors is an integer number (1691928).

Almost surely, 2^11561221 is an apocalyptic number.

It is an amenable number.

11561221 is a deficient number, since it is larger than the sum of its proper divisors (1974203).

11561221 is an equidigital number, since it uses as much as digits as its factorization.

11561221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40331.

The product of its digits is 120, while the sum is 19.

The square root of 11561221 is about 3400.1795540824. The cubic root of 11561221 is about 226.1177043696.

Adding to 11561221 its reverse (12216511), we get a palindrome (23777732).

The spelling of 11561221 in words is "eleven million, five hundred sixty-one thousand, two hundred twenty-one".