1666658771 has 2 divisors, whose sum is σ = 1666658772. Its totient is φ = 1666658770.

The previous prime is 1666658761. The next prime is 1666658779. The reversal of 1666658771 is 1778566661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666658771 - 2²² = 1662464467 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1666658779) 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, 833329385 + 833329386.

It is an arithmetic number, because the mean of its divisors is an integer number (833329386).

Almost surely, 2^1666658771 is an apocalyptic number.

1666658771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666658771 is an equidigital number, since it uses as much as digits as its factorization.

1666658771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 53.

The square root of 1666658771 is about 40824.7323444992. The cubic root of 1666658771 is about 1185.6292292241.

The spelling of 1666658771 in words is "one billion, six hundred sixty-six million, six hundred fifty-eight thousand, seven hundred seventy-one".