1666711663 has 2 divisors, whose sum is σ = 1666711664. Its totient is φ = 1666711662.

The previous prime is 1666711661. The next prime is 1666711679. The reversal of 1666711663 is 3661176661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666711663 - 2¹ = 1666711661 is a prime.

It is a super-3 number, since 3×1666711663³ (a number of 29 digits) contains 333 as substring.

Together with 1666711661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666711661) 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, 833355831 + 833355832.

It is an arithmetic number, because the mean of its divisors is an integer number (833355832).

Almost surely, 2^1666711663 is an apocalyptic number.

1666711663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666711663 is an equidigital number, since it uses as much as digits as its factorization.

1666711663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The square root of 1666711663 is about 40825.3801329516. The cubic root of 1666711663 is about 1185.6417712111.

The spelling of 1666711663 in words is "one billion, six hundred sixty-six million, seven hundred eleven thousand, six hundred sixty-three".