28508787289 has 4 divisors (see below), whose sum is σ = 28761077556. Its totient is φ = 28256497024.

The previous prime is 28508787283. The next prime is 28508787371. The reversal of 28508787289 is 98278780582.

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 6041175625 + 22467611664 = 77725^2 + 149892^2 .

It is a cyclic number.

It is not a de Polignac number, because 28508787289 - 2⁵ = 28508787257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28508787289.

It is not an unprimeable number, because it can be changed into a prime (28508787283) 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, 126144964 + ... + 126145189.

It is an arithmetic number, because the mean of its divisors is an integer number (7190269389).

Almost surely, 2^28508787289 is an apocalyptic number.

It is an amenable number.

28508787289 is a deficient number, since it is larger than the sum of its proper divisors (252290267).

28508787289 is a wasteful number, since it uses less digits than its factorization.

28508787289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252290266.

The product of its (nonzero) digits is 36126720, while the sum is 64.

The spelling of 28508787289 in words is "twenty-eight billion, five hundred eight million, seven hundred eighty-seven thousand, two hundred eighty-nine".