1666109852651 has 2 divisors, whose sum is σ = 1666109852652. Its totient is φ = 1666109852650.

The previous prime is 1666109852597. The next prime is 1666109852669. The reversal of 1666109852651 is 1562589016661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666109852651 - 2³⁰ = 1665036110827 is a prime.

It is a super-2 number, since 2×1666109852651² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1666109857651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833054926325 + 833054926326.

It is an arithmetic number, because the mean of its divisors is an integer number (833054926326).

Almost surely, 2^{1666109852651} is an apocalyptic number.

1666109852651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666109852651 is an equidigital number, since it uses as much as digits as its factorization.

1666109852651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4665600, while the sum is 56.

The spelling of 1666109852651 in words is "one trillion, six hundred sixty-six billion, one hundred nine million, eight hundred fifty-two thousand, six hundred fifty-one".