16661121112147 has 2 divisors, whose sum is σ = 16661121112148. Its totient is φ = 16661121112146.

The previous prime is 16661121112127. The next prime is 16661121112187. The reversal of 16661121112147 is 74121112116661.

It is a happy number.

It is an a-pointer prime, because the next prime (16661121112187) can be obtained adding 16661121112147 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16661121112147 is a prime.

It is not a weakly prime, because it can be changed into another prime (16661121112127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330560556073 + 8330560556074.

It is an arithmetic number, because the mean of its divisors is an integer number (8330560556074).

Almost surely, 2^{16661121112147} is an apocalyptic number.

16661121112147 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661121112147 is an equidigital number, since it uses as much as digits as its factorization.

16661121112147 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The spelling of 16661121112147 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty-one million, one hundred twelve thousand, one hundred forty-seven".