28879813 has 4 divisors (see below), whose sum is σ = 28929600. Its totient is φ = 28830028.

The previous prime is 28879783. The next prime is 28879831. The reversal of 28879813 is 31897882.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28879813 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 (28879843) 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, 24013 + ... + 25186.

It is an arithmetic number, because the mean of its divisors is an integer number (7232400).

Almost surely, 2^28879813 is an apocalyptic number.

It is an amenable number.

28879813 is a deficient number, since it is larger than the sum of its proper divisors (49787).

28879813 is an equidigital number, since it uses as much as digits as its factorization.

28879813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49786.

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

The square root of 28879813 is about 5373.9941384412. The cubic root of 28879813 is about 306.8066666748.

It can be divided in two parts, 28879 and 813, that added together give a palindrome (29692).

The spelling of 28879813 in words is "twenty-eight million, eight hundred seventy-nine thousand, eight hundred thirteen".