16661121112172 has 12 divisors (see below), whose sum is σ = 29172748078320. Its totient is φ = 8326050232656.

The previous prime is 16661121112147. The next prime is 16661121112187. The reversal of 16661121112172 is 27121112116661.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1127572547 + ... + 1127587322.

It is an arithmetic number, because the mean of its divisors is an integer number (2431062339860).

Almost surely, 2^{16661121112172} is an apocalyptic number.

It is an amenable number.

16661121112172 is a deficient number, since it is larger than the sum of its proper divisors (12511626966148).

16661121112172 is a wasteful number, since it uses less digits than its factorization.

16661121112172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255161720 (or 2255161718 counting only the distinct ones).

The product of its digits is 12096, while the sum is 38.

The spelling of 16661121112172 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty-one million, one hundred twelve thousand, one hundred seventy-two".