1666060616491 has 2 divisors, whose sum is σ = 1666060616492. Its totient is φ = 1666060616490.

The previous prime is 1666060616477. The next prime is 1666060616531. The reversal of 1666060616491 is 1946160606661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666060616491 - 2²⁵ = 1666027062059 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666060616791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833030308245 + 833030308246.

It is an arithmetic number, because the mean of its divisors is an integer number (833030308246).

Almost surely, 2^{1666060616491} is an apocalyptic number.

1666060616491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666060616491 is an equidigital number, since it uses as much as digits as its factorization.

1666060616491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1679616, while the sum is 52.

The spelling of 1666060616491 in words is "one trillion, six hundred sixty-six billion, sixty million, six hundred sixteen thousand, four hundred ninety-one".