12170021 has 2 divisors, whose sum is σ = 12170022. Its totient is φ = 12170020.

The previous prime is 12170017. The next prime is 12170027. The reversal of 12170021 is 12007121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6477025 + 5692996 = 2545^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 12170021 - 2² = 12170017 is a prime.

It is a super-2 number, since 2×12170021² = 296218822280882, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12169978 and 12170005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12170027) 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, 6085010 + 6085011.

It is an arithmetic number, because the mean of its divisors is an integer number (6085011).

Almost surely, 2^12170021 is an apocalyptic number.

It is an amenable number.

12170021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12170021 is an equidigital number, since it uses as much as digits as its factorization.

12170021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 12170021 is about 3488.5557183453. Note that the first 3 decimals coincide. The cubic root of 12170021 is about 230.0190343415.

Adding to 12170021 its reverse (12007121), we get a palindrome (24177142).

The spelling of 12170021 in words is "twelve million, one hundred seventy thousand, twenty-one".