28256231217 has 16 divisors (see below), whose sum is σ = 37805302080. Its totient is φ = 18772416000.

The previous prime is 28256231173. The next prime is 28256231219. The reversal of 28256231217 is 71213265282.

It is not a de Polignac number, because 28256231217 - 2²⁸ = 27987795761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28256231219) 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 15 ways as a sum of consecutive naturals, for example, 1301709 + ... + 1323237.

It is an arithmetic number, because the mean of its divisors is an integer number (2362831380).

Almost surely, 2^28256231217 is an apocalyptic number.

It is an amenable number.

28256231217 is a deficient number, since it is larger than the sum of its proper divisors (9549070863).

28256231217 is a wasteful number, since it uses less digits than its factorization.

28256231217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23024.

The product of its digits is 80640, while the sum is 39.

Adding to 28256231217 its reverse (71213265282), we get a palindrome (99469496499).

The spelling of 28256231217 in words is "twenty-eight billion, two hundred fifty-six million, two hundred thirty-one thousand, two hundred seventeen".