11185721 has 2 divisors, whose sum is σ = 11185722. Its totient is φ = 11185720.

The previous prime is 11185709. The next prime is 11185723. The reversal of 11185721 is 12758111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10471696 + 714025 = 3236^2 + 845^2 .

It is an emirp because it is prime and its reverse (12758111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11185721 - 2¹⁴ = 11169337 is a prime.

Together with 11185723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11185723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5592860 + 5592861.

It is an arithmetic number, because the mean of its divisors is an integer number (5592861).

Almost surely, 2^11185721 is an apocalyptic number.

It is an amenable number.

11185721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11185721 is an equidigital number, since it uses as much as digits as its factorization.

11185721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 560, while the sum is 26.

The square root of 11185721 is about 3344.5060920859. The cubic root of 11185721 is about 223.6426660794.

The spelling of 11185721 in words is "eleven million, one hundred eighty-five thousand, seven hundred twenty-one".