28811399 has 4 divisors (see below), whose sum is σ = 28970760. Its totient is φ = 28652040.

The previous prime is 28811359. The next prime is 28811401. The reversal of 28811399 is 99311882.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28811399 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 (28811359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79409 + ... + 79770.

It is an arithmetic number, because the mean of its divisors is an integer number (7242690).

Almost surely, 2^28811399 is an apocalyptic number.

28811399 is a deficient number, since it is larger than the sum of its proper divisors (159361).

28811399 is a wasteful number, since it uses less digits than its factorization.

28811399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159360.

The product of its digits is 31104, while the sum is 41.

The square root of 28811399 is about 5367.6250800517. The cubic root of 28811399 is about 306.5642081844.

The spelling of 28811399 in words is "twenty-eight million, eight hundred eleven thousand, three hundred ninety-nine".