11505281 has 2 divisors, whose sum is σ = 11505282. Its totient is φ = 11505280.

The previous prime is 11505259. The next prime is 11505287. The reversal of 11505281 is 18250511.

11505281 is digitally balanced in base 2, 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., 11498881 + 6400 = 3391^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 11505281 - 2⁶ = 11505217 is a prime.

It is a super-2 number, since 2×11505281² = 264742981777922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (11505287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5752640 + 5752641.

It is an arithmetic number, because the mean of its divisors is an integer number (5752641).

Almost surely, 2^11505281 is an apocalyptic number.

It is an amenable number.

11505281 is a deficient number, since it is larger than the sum of its proper divisors (1).

11505281 is an equidigital number, since it uses as much as digits as its factorization.

11505281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 11505281 is about 3391.9435431622. The cubic root of 11505281 is about 225.7524176770.

Adding to 11505281 its reverse (18250511), we get a palindrome (29755792).

The spelling of 11505281 in words is "eleven million, five hundred five thousand, two hundred eighty-one".