11531521 has 2 divisors, whose sum is σ = 11531522. Its totient is φ = 11531520.

The previous prime is 11531519. The next prime is 11531539. The reversal of 11531521 is 12513511.

11531521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10491121 + 1040400 = 3239^2 + 1020^2 .

It is a cyclic number.

It is not a de Polignac number, because 11531521 - 2¹ = 11531519 is a prime.

Together with 11531519, 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 (11531561) 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, 5765760 + 5765761.

It is an arithmetic number, because the mean of its divisors is an integer number (5765761).

Almost surely, 2^11531521 is an apocalyptic number.

It is an amenable number.

11531521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11531521 is an equidigital number, since it uses as much as digits as its factorization.

11531521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 150, while the sum is 19.

The square root of 11531521 is about 3395.8093291585. The cubic root of 11531521 is about 225.9239112640.

The spelling of 11531521 in words is "eleven million, five hundred thirty-one thousand, five hundred twenty-one".