16661898189169 has 4 divisors (see below), whose sum is σ = 16731034696420. Its totient is φ = 16592761681920.

The previous prime is 16661898189163. The next prime is 16661898189191. The reversal of 16661898189169 is 96198189816661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5509404172944 + 11152494016225 = 2347212^2 + 3339535^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661898189169 - 2⁵ = 16661898189137 is a prime.

It is a super-2 number, since 2×16661898189169² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16661898189163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34568253264 + ... + 34568253745.

It is an arithmetic number, because the mean of its divisors is an integer number (4182758674105).

Almost surely, 2^{16661898189169} is an apocalyptic number.

It is an amenable number.

16661898189169 is a deficient number, since it is larger than the sum of its proper divisors (69136507251).

16661898189169 is an equidigital number, since it uses as much as digits as its factorization.

16661898189169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69136507250.

The product of its digits is 483729408, while the sum is 79.

The spelling of 16661898189169 in words is "sixteen trillion, six hundred sixty-one billion, eight hundred ninety-eight million, one hundred eighty-nine thousand, one hundred sixty-nine".