11289721 has 2 divisors, whose sum is σ = 11289722. Its totient is φ = 11289720.

The previous prime is 11289659. The next prime is 11289731. The reversal of 11289721 is 12798211.

11289721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11289600 + 121 = 3360^2 + 11^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11289721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11289731) 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 as a sum of consecutive naturals, namely, 5644860 + 5644861.

It is an arithmetic number, because the mean of its divisors is an integer number (5644861).

Almost surely, 2^11289721 is an apocalyptic number.

It is an amenable number.

11289721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11289721 is an equidigital number, since it uses as much as digits as its factorization.

11289721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 31.

The square root of 11289721 is about 3360.0180059041. The cubic root of 11289721 is about 224.3336399790. Note that the first 3 decimals are identical.

The spelling of 11289721 in words is "eleven million, two hundred eighty-nine thousand, seven hundred twenty-one".