12173521 has 2 divisors, whose sum is σ = 12173522. Its totient is φ = 12173520.

The previous prime is 12173519. The next prime is 12173531. The reversal of 12173521 is 12537121.

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., 12173121 + 400 = 3489^2 + 20^2 .

It is an emirp because it is prime and its reverse (12537121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12173521 - 2¹ = 12173519 is a prime.

It is a super-2 number, since 2×12173521² = 296389227074882, which contains 22 as substring.

Together with 12173519, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12173492 and 12173501.

It is not a weakly prime, because it can be changed into another prime (12173501) 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, 6086760 + 6086761.

It is an arithmetic number, because the mean of its divisors is an integer number (6086761).

Almost surely, 2^12173521 is an apocalyptic number.

It is an amenable number.

12173521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12173521 is an equidigital number, since it uses as much as digits as its factorization.

12173521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 420, while the sum is 22.

The square root of 12173521 is about 3489.0573225443. The cubic root of 12173521 is about 230.0410827684.

The spelling of 12173521 in words is "twelve million, one hundred seventy-three thousand, five hundred twenty-one".