28643823 has 24 divisors (see below), whose sum is σ = 44907408. Its totient is φ = 17488512.

The previous prime is 28643819. The next prime is 28643837. The reversal of 28643823 is 32834682.

28643823 is a `hidden beast` number, since 2 + 8 + 643 + 8 + 2 + 3 = 666.

It is not a de Polignac number, because 28643823 - 2² = 28643819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28643843) 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, 15136 + ... + 16922.

It is an arithmetic number, because the mean of its divisors is an integer number (1871142).

Almost surely, 2^28643823 is an apocalyptic number.

28643823 is a deficient number, since it is larger than the sum of its proper divisors (16263585).

28643823 is a wasteful number, since it uses less digits than its factorization.

28643823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943 (or 1940 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 28643823 is about 5351.9924327301. The cubic root of 28643823 is about 305.9686947341.

The spelling of 28643823 in words is "twenty-eight million, six hundred forty-three thousand, eight hundred twenty-three".