28233121789 has 4 divisors (see below), whose sum is σ = 28619876956. Its totient is φ = 27846366624.

The previous prime is 28233121781. The next prime is 28233121817. The reversal of 28233121789 is 98712133282.

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 15047192889 + 13185928900 = 122667^2 + 114830^2 .

It is a cyclic number.

It is not a de Polignac number, because 28233121789 - 2³ = 28233121781 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 (28233121781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193377474 + ... + 193377619.

It is an arithmetic number, because the mean of its divisors is an integer number (7154969239).

Almost surely, 2^28233121789 is an apocalyptic number.

It is an amenable number.

28233121789 is a deficient number, since it is larger than the sum of its proper divisors (386755167).

28233121789 is an equidigital number, since it uses as much as digits as its factorization.

28233121789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386755166.

The product of its digits is 290304, while the sum is 46.

The spelling of 28233121789 in words is "twenty-eight billion, two hundred thirty-three million, one hundred twenty-one thousand, seven hundred eighty-nine".