12135521 has 2 divisors, whose sum is σ = 12135522. Its totient is φ = 12135520.

The previous prime is 12135499. The next prime is 12135551. The reversal of 12135521 is 12553121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11316496 + 819025 = 3364^2 + 905^2 .

It is a cyclic number.

It is not a de Polignac number, because 12135521 - 2¹⁰ = 12134497 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12135493 and 12135502.

It is not a weakly prime, because it can be changed into another prime (12135551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6067760 + 6067761.

It is an arithmetic number, because the mean of its divisors is an integer number (6067761).

Almost surely, 2^12135521 is an apocalyptic number.

It is an amenable number.

12135521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12135521 is an equidigital number, since it uses as much as digits as its factorization.

12135521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 300, while the sum is 20.

The square root of 12135521 is about 3483.6074692766. The cubic root of 12135521 is about 229.8014733016.

Adding to 12135521 its reverse (12553121), we get a palindrome (24688642).

The spelling of 12135521 in words is "twelve million, one hundred thirty-five thousand, five hundred twenty-one".