28129865947 has 6 divisors (see below), whose sum is σ = 28785174308. Its totient is φ = 27474608784.

The previous prime is 28129865887. The next prime is 28129865963. The reversal of 28129865947 is 74956892182.

It is not a de Polignac number, because 28129865947 - 2¹¹ = 28129863899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28129865447) 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 5 ways as a sum of consecutive naturals, for example, 1087023 + ... + 1112599.

Almost surely, 2^28129865947 is an apocalyptic number.

28129865947 is a deficient number, since it is larger than the sum of its proper divisors (655308361).

28129865947 is an frugal number, since it uses more digits than its factorization.

28129865947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51197 (or 25620 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 61.

The spelling of 28129865947 in words is "twenty-eight billion, one hundred twenty-nine million, eight hundred sixty-five thousand, nine hundred forty-seven".