28391989589 has 4 divisors (see below), whose sum is σ = 28394353356. Its totient is φ = 28389625824.

The previous prime is 28391989573. The next prime is 28391989603. The reversal of 28391989589 is 98598919382.

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 1703212900 + 26688776689 = 41270^2 + 163367^2 .

It is a cyclic number.

It is not a de Polignac number, because 28391989589 - 2⁴ = 28391989573 is a prime.

It is a super-2 number, since 2×28391989589² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28391989789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1163774 + ... + 1187919.

It is an arithmetic number, because the mean of its divisors is an integer number (7098588339).

Almost surely, 2^28391989589 is an apocalyptic number.

It is an amenable number.

28391989589 is a deficient number, since it is larger than the sum of its proper divisors (2363767).

28391989589 is a wasteful number, since it uses less digits than its factorization.

28391989589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2363766.

The product of its digits is 100776960, while the sum is 71.

The spelling of 28391989589 in words is "twenty-eight billion, three hundred ninety-one million, nine hundred eighty-nine thousand, five hundred eighty-nine".