28718013 has 4 divisors (see below), whose sum is σ = 38290688. Its totient is φ = 19145340.

The previous prime is 28717993. The next prime is 28718017. The reversal of 28718013 is 31081782.

It is a happy number.

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 not a de Polignac number, because 28718013 - 2⁸ = 28717757 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 (28718017) 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, 4786333 + ... + 4786338.

It is an arithmetic number, because the mean of its divisors is an integer number (9572672).

Almost surely, 2^28718013 is an apocalyptic number.

It is an amenable number.

28718013 is a deficient number, since it is larger than the sum of its proper divisors (9572675).

28718013 is an equidigital number, since it uses as much as digits as its factorization.

28718013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9572674.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 28718013 is about 5358.9190141296. The cubic root of 28718013 is about 306.2326288634.

Adding to 28718013 its reverse (31081782), we get a palindrome (59799795).

The spelling of 28718013 in words is "twenty-eight million, seven hundred eighteen thousand, thirteen".