28319513 has 4 divisors (see below), whose sum is σ = 28425060. Its totient is φ = 28213968.

The previous prime is 28319497. The next prime is 28319531. The reversal of 28319513 is 31591382.

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 6901129 + 21418384 = 2627^2 + 4628^2 .

It is a cyclic number.

It is not a de Polignac number, because 28319513 - 2⁴ = 28319497 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28319513.

It is not an unprimeable number, because it can be changed into a prime (28319563) 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, 52370 + ... + 52907.

It is an arithmetic number, because the mean of its divisors is an integer number (7106265).

Almost surely, 2^28319513 is an apocalyptic number.

It is an amenable number.

28319513 is a deficient number, since it is larger than the sum of its proper divisors (105547).

28319513 is a wasteful number, since it uses less digits than its factorization.

28319513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105546.

The product of its digits is 6480, while the sum is 32.

The square root of 28319513 is about 5321.6081216114. The cubic root of 28319513 is about 304.8095666920.

The spelling of 28319513 in words is "twenty-eight million, three hundred nineteen thousand, five hundred thirteen".