28668781543 has 4 divisors (see below), whose sum is σ = 28707893848. Its totient is φ = 28629669240.

The previous prime is 28668781513. The next prime is 28668781597. The reversal of 28668781543 is 34518786682.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28668781543 - 2⁵ = 28668781511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28668781513) 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, 19555053 + ... + 19556518.

It is an arithmetic number, because the mean of its divisors is an integer number (7176973462).

Almost surely, 2^28668781543 is an apocalyptic number.

28668781543 is a deficient number, since it is larger than the sum of its proper divisors (39112305).

28668781543 is an equidigital number, since it uses as much as digits as its factorization.

28668781543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39112304.

The product of its digits is 15482880, while the sum is 58.

The spelling of 28668781543 in words is "twenty-eight billion, six hundred sixty-eight million, seven hundred eighty-one thousand, five hundred forty-three".