16661657223149 has 2 divisors, whose sum is σ = 16661657223150. Its totient is φ = 16661657223148.

The previous prime is 16661657223061. The next prime is 16661657223161. The reversal of 16661657223149 is 94132275616661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10450187655625 + 6211469567524 = 3232675^2 + 2492282^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661657223149 - 2²⁰ = 16661656174573 is a prime.

It is a super-2 number, since 2×16661657223149² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16661659223149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330828611574 + 8330828611575.

It is an arithmetic number, because the mean of its divisors is an integer number (8330828611575).

Almost surely, 2^{16661657223149} is an apocalyptic number.

It is an amenable number.

16661657223149 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661657223149 is an equidigital number, since it uses as much as digits as its factorization.

16661657223149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19595520, while the sum is 59.

The spelling of 16661657223149 in words is "sixteen trillion, six hundred sixty-one billion, six hundred fifty-seven million, two hundred twenty-three thousand, one hundred forty-nine".