28817893 has 4 divisors (see below), whose sum is σ = 31034668. Its totient is φ = 26601120.

The previous prime is 28817863. The next prime is 28817917. The reversal of 28817893 is 39871882.

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 1954404 + 26863489 = 1398^2 + 5183^2 .

It is not a de Polignac number, because 28817893 - 2⁹ = 28817381 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 (28817843) 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, 1108368 + ... + 1108393.

It is an arithmetic number, because the mean of its divisors is an integer number (7758667).

Almost surely, 2^28817893 is an apocalyptic number.

It is an amenable number.

28817893 is a deficient number, since it is larger than the sum of its proper divisors (2216775).

28817893 is a wasteful number, since it uses less digits than its factorization.

28817893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2216774.

The product of its digits is 193536, while the sum is 46.

The square root of 28817893 is about 5368.2299689935. The cubic root of 28817893 is about 306.5872393281.

It can be divided in two parts, 288 and 17893, that added together give a palindrome (18181).

The spelling of 28817893 in words is "twenty-eight million, eight hundred seventeen thousand, eight hundred ninety-three".