11280721 has 2 divisors, whose sum is σ = 11280722. Its totient is φ = 11280720.

The previous prime is 11280701. The next prime is 11280733. The reversal of 11280721 is 12708211.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8179600 + 3101121 = 2860^2 + 1761^2 .

It is an emirp because it is prime and its reverse (12708211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11280721 - 2⁷ = 11280593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11280692 and 11280701.

It is not a weakly prime, because it can be changed into another prime (11280701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5640360 + 5640361.

It is an arithmetic number, because the mean of its divisors is an integer number (5640361).

Almost surely, 2^11280721 is an apocalyptic number.

It is an amenable number.

11280721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11280721 is an equidigital number, since it uses as much as digits as its factorization.

11280721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 11280721 is about 3358.6784603472. The cubic root of 11280721 is about 224.2740123022.

Adding to 11280721 its reverse (12708211), we get a palindrome (23988932).

The spelling of 11280721 in words is "eleven million, two hundred eighty thousand, seven hundred twenty-one".