1666643327 has 2 divisors, whose sum is σ = 1666643328. Its totient is φ = 1666643326.

The previous prime is 1666643299. The next prime is 1666643333. The reversal of 1666643327 is 7233466661.

It is a strong prime.

It is an emirp because it is prime and its reverse (7233466661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1666643327 - 2¹² = 1666639231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666643347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833321663 + 833321664.

It is an arithmetic number, because the mean of its divisors is an integer number (833321664).

Almost surely, 2^1666643327 is an apocalyptic number.

1666643327 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666643327 is an equidigital number, since it uses as much as digits as its factorization.

1666643327 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 44.

The square root of 1666643327 is about 40824.5431940150. The cubic root of 1666643327 is about 1185.6255670239.

The spelling of 1666643327 in words is "one billion, six hundred sixty-six million, six hundred forty-three thousand, three hundred twenty-seven".