11287921 has 2 divisors, whose sum is σ = 11287922. Its totient is φ = 11287920.

The previous prime is 11287891. The next prime is 11287933. The reversal of 11287921 is 12978211.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10497600 + 790321 = 3240^2 + 889^2 .

It is an emirp because it is prime and its reverse (12978211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11287921 - 2²³ = 2899313 is a prime.

It is not a weakly prime, because it can be changed into another prime (11287951) 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, 5643960 + 5643961.

It is an arithmetic number, because the mean of its divisors is an integer number (5643961).

Almost surely, 2^11287921 is an apocalyptic number.

It is an amenable number.

11287921 is a deficient number, since it is larger than the sum of its proper divisors (1).

11287921 is an equidigital number, since it uses as much as digits as its factorization.

11287921 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 11287921 is about 3359.7501395193. The cubic root of 11287921 is about 224.3217169794.

The spelling of 11287921 in words is "eleven million, two hundred eighty-seven thousand, nine hundred twenty-one".