28168929968481 has 27 divisors (see below), whose sum is σ = 42943123592499. Its totient is φ = 17790712070112.

The previous prime is 28168929968471. The next prime is 28168929968563. The reversal of 28168929968481 is 18486992986182.

The square root of 28168929968481 is 5307441.

It is a perfect power (a square), and thus also a powerful number.

28168929968481 is a `hidden beast` number, since 28 + 1 + 6 + 8 + 9 + 29 + 96 + 8 + 481 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11831295312225 + 16337634656256 = 3439665^2 + 4041984^2 .

It is not a de Polignac number, because 28168929968481 - 2⁷ = 28168929968353 is a prime.

It is a super-2 number, since 2×28168929968481² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28168929968481.

It is not an unprimeable number, because it can be changed into a prime (28168929968471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 302477581 + ... + 302570693.

Almost surely, 2^{28168929968481} is an apocalyptic number.

28168929968481 is the 5307441-st square number.

28168929968481 is the 2653721-st centered octagonal number.

It is an amenable number.

28168929968481 is a deficient number, since it is larger than the sum of its proper divisors (14774193624018).

28168929968481 is an frugal number, since it uses more digits than its factorization.

28168929968481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186270 (or 93135 counting only the distinct ones).

The product of its digits is 1719926784, while the sum is 81.

The spelling of 28168929968481 in words is "twenty-eight trillion, one hundred sixty-eight billion, nine hundred twenty-nine million, nine hundred sixty-eight thousand, four hundred eighty-one".