28236813811 has 4 divisors (see below), whose sum is σ = 29464501392. Its totient is φ = 27009126232.

The previous prime is 28236813797. The next prime is 28236813823. The reversal of 28236813811 is 11831863282.

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

It is a cyclic number.

It is not a de Polignac number, because 28236813811 - 2⁹ = 28236813299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28236813911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 613843756 + ... + 613843801.

It is an arithmetic number, because the mean of its divisors is an integer number (7366125348).

Almost surely, 2^28236813811 is an apocalyptic number.

28236813811 is a deficient number, since it is larger than the sum of its proper divisors (1227687581).

28236813811 is a wasteful number, since it uses less digits than its factorization.

28236813811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227687580.

The product of its digits is 110592, while the sum is 43.

The spelling of 28236813811 in words is "twenty-eight billion, two hundred thirty-six million, eight hundred thirteen thousand, eight hundred eleven".