1220166217 has 2 divisors, whose sum is σ = 1220166218. Its totient is φ = 1220166216.

The previous prime is 1220166193. The next prime is 1220166223. The reversal of 1220166217 is 7126610221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1130371641 + 89794576 = 33621^2 + 9476^2 .

It is an emirp because it is prime and its reverse (7126610221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220166217 is a prime.

It is not a weakly prime, because it can be changed into another prime (1220166247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610083108 + 610083109.

It is an arithmetic number, because the mean of its divisors is an integer number (610083109).

Almost surely, 2^1220166217 is an apocalyptic number.

It is an amenable number.

1220166217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220166217 is an equidigital number, since it uses as much as digits as its factorization.

1220166217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1220166217 is about 34930.8777015408. The cubic root of 1220166217 is about 1068.5782546682.

Adding to 1220166217 its reverse (7126610221), we get a palindrome (8346776438).

The spelling of 1220166217 in words is "one billion, two hundred twenty million, one hundred sixty-six thousand, two hundred seventeen".