16661121112187 has 2 divisors, whose sum is σ = 16661121112188. Its totient is φ = 16661121112186.

The previous prime is 16661121112147. The next prime is 16661121112189. The reversal of 16661121112187 is 78121112116661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16661121112187 - 2⁸ = 16661121111931 is a prime.

Together with 16661121112189, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16661121112189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330560556093 + 8330560556094.

It is an arithmetic number, because the mean of its divisors is an integer number (8330560556094).

Almost surely, 2^{16661121112187} is an apocalyptic number.

16661121112187 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661121112187 is an equidigital number, since it uses as much as digits as its factorization.

16661121112187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 44.

The spelling of 16661121112187 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty-one million, one hundred twelve thousand, one hundred eighty-seven".