28806813 has 16 divisors (see below), whose sum is σ = 48773760. Its totient is φ = 16460928.

The previous prime is 28806779. The next prime is 28806821. The reversal of 28806813 is 31860882.

It is not a de Polignac number, because 28806813 - 2¹² = 28802717 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28801813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76020 + ... + 76397.

It is an arithmetic number, because the mean of its divisors is an integer number (3048360).

Almost surely, 2^28806813 is an apocalyptic number.

It is an amenable number.

28806813 is a deficient number, since it is larger than the sum of its proper divisors (19966947).

28806813 is a wasteful number, since it uses less digits than its factorization.

28806813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152433 (or 152427 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 28806813 is about 5367.1978722607. The cubic root of 28806813 is about 306.5479417284.

The spelling of 28806813 in words is "twenty-eight million, eight hundred six thousand, eight hundred thirteen".