12221917 has 2 divisors, whose sum is σ = 12221918. Its totient is φ = 12221916.

The previous prime is 12221893. The next prime is 12221969. The reversal of 12221917 is 71912221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9696996 + 2524921 = 3114^2 + 1589^2 .

It is an emirp because it is prime and its reverse (71912221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12221917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12221891 and 12221900.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12221117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6110958 + 6110959.

It is an arithmetic number, because the mean of its divisors is an integer number (6110959).

Almost surely, 2^12221917 is an apocalyptic number.

It is an amenable number.

12221917 is a deficient number, since it is larger than the sum of its proper divisors (1).

12221917 is an equidigital number, since it uses as much as digits as its factorization.

12221917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 25.

The square root of 12221917 is about 3495.9858409324. The cubic root of 12221917 is about 230.3455235165.

The spelling of 12221917 in words is "twelve million, two hundred twenty-one thousand, nine hundred seventeen".