12345521 has 2 divisors, whose sum is σ = 12345522. Its totient is φ = 12345520.

The previous prime is 12345517. The next prime is 12345523. The reversal of 12345521 is 12554321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6195121 + 6150400 = 2489^2 + 2480^2 .

It is a cyclic number.

It is not a de Polignac number, because 12345521 - 2² = 12345517 is a prime.

It is a super-2 number, since 2×12345521² = 304823777522882, which contains 22 as substring.

Together with 12345523, 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 (12345523) 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, 6172760 + 6172761.

It is an arithmetic number, because the mean of its divisors is an integer number (6172761).

Almost surely, 2^12345521 is an apocalyptic number.

It is an amenable number.

12345521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12345521 is an equidigital number, since it uses as much as digits as its factorization.

12345521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 23.

The square root of 12345521 is about 3513.6193590086. The cubic root of 12345521 is about 231.1194387426.

Subtracting from 12345521 its product of digits (1200), we obtain a palindrome (12344321).

Adding to 12345521 its reverse (12554321), we get a palindrome (24899842).

The spelling of 12345521 in words is "twelve million, three hundred forty-five thousand, five hundred twenty-one".