1664233217 has 2 divisors, whose sum is σ = 1664233218. Its totient is φ = 1664233216.

The previous prime is 1664233213. The next prime is 1664233243. The reversal of 1664233217 is 7123324661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 991557121 + 672676096 = 31489^2 + 25936^2 .

It is an emirp because it is prime and its reverse (7123324661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1664233217 - 2² = 1664233213 is a prime.

It is not a weakly prime, because it can be changed into another prime (1664233213) 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, 832116608 + 832116609.

It is an arithmetic number, because the mean of its divisors is an integer number (832116609).

Almost surely, 2^1664233217 is an apocalyptic number.

It is an amenable number.

1664233217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664233217 is an equidigital number, since it uses as much as digits as its factorization.

1664233217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 35.

The square root of 1664233217 is about 40795.0146096309. The cubic root of 1664233217 is about 1185.0537857099.

Adding to 1664233217 its reverse (7123324661), we get a palindrome (8787557878).

The spelling of 1664233217 in words is "one billion, six hundred sixty-four million, two hundred thirty-three thousand, two hundred seventeen".