28690393289 has 4 divisors (see below), whose sum is σ = 28707301524. Its totient is φ = 28673485056.

The previous prime is 28690393261. The next prime is 28690393297. The reversal of 28690393289 is 98239309682.

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 17073864889 + 11616528400 = 130667^2 + 107780^2 .

It is a cyclic number.

It is not a de Polignac number, because 28690393289 - 2¹² = 28690389193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28690393229) 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, 8451572 + ... + 8454965.

It is an arithmetic number, because the mean of its divisors is an integer number (7176825381).

Almost surely, 2^28690393289 is an apocalyptic number.

It is an amenable number.

28690393289 is a deficient number, since it is larger than the sum of its proper divisors (16908235).

28690393289 is a wasteful number, since it uses less digits than its factorization.

28690393289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16908234.

The product of its (nonzero) digits is 10077696, while the sum is 59.

The spelling of 28690393289 in words is "twenty-eight billion, six hundred ninety million, three hundred ninety-three thousand, two hundred eighty-nine".