28716813 has 24 divisors (see below), whose sum is σ = 42539640. Its totient is φ = 18662400.

The previous prime is 28716763. The next prime is 28716823. The reversal of 28716813 is 31861782.

It can be written as a sum of positive squares in 4 ways, for example, as 16793604 + 11923209 = 4098^2 + 3453^2 .

It is not a de Polignac number, because 28716813 - 2¹⁷ = 28585741 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28716823) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71413 + ... + 71813.

It is an arithmetic number, because the mean of its divisors is an integer number (1772485).

Almost surely, 2^28716813 is an apocalyptic number.

It is an amenable number.

28716813 is a deficient number, since it is larger than the sum of its proper divisors (13822827).

28716813 is a wasteful number, since it uses less digits than its factorization.

28716813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 586 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 28716813 is about 5358.8070500812. The cubic root of 28716813 is about 306.2283634305.

The spelling of 28716813 in words is "twenty-eight million, seven hundred sixteen thousand, eight hundred thirteen".