1666885511 has 2 divisors, whose sum is σ = 1666885512. Its totient is φ = 1666885510.

The previous prime is 1666885501. The next prime is 1666885607. The reversal of 1666885511 is 1155886661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666885511 - 2¹⁰ = 1666884487 is a prime.

It is a super-2 number, since 2×1666885511² = 5557014613563462242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666885501) 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, 833442755 + 833442756.

It is an arithmetic number, because the mean of its divisors is an integer number (833442756).

Almost surely, 2^1666885511 is an apocalyptic number.

1666885511 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666885511 is an equidigital number, since it uses as much as digits as its factorization.

1666885511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 47.

The square root of 1666885511 is about 40827.5092431561. The cubic root of 1666885511 is about 1185.6829929551.

The spelling of 1666885511 in words is "one billion, six hundred sixty-six million, eight hundred eighty-five thousand, five hundred eleven".