1665221227 has 2 divisors, whose sum is σ = 1665221228. Its totient is φ = 1665221226.

The previous prime is 1665221221. The next prime is 1665221293. The reversal of 1665221227 is 7221225661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1665221227 - 2¹⁹ = 1664696939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665221192 and 1665221201.

It is not a weakly prime, because it can be changed into another prime (1665221221) 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, 832610613 + 832610614.

It is an arithmetic number, because the mean of its divisors is an integer number (832610614).

Almost surely, 2^1665221227 is an apocalyptic number.

1665221227 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665221227 is an equidigital number, since it uses as much as digits as its factorization.

1665221227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 34.

The square root of 1665221227 is about 40807.1222582529. The cubic root of 1665221227 is about 1185.2882507187.

Adding to 1665221227 its reverse (7221225661), we get a palindrome (8886446888).

The spelling of 1665221227 in words is "one billion, six hundred sixty-five million, two hundred twenty-one thousand, two hundred twenty-seven".