28393999 has 4 divisors (see below), whose sum is σ = 29888440. Its totient is φ = 26899560.

The previous prime is 28393993. The next prime is 28394027. The reversal of 28393999 is 99939382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28393999 - 2¹⁹ = 27869711 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 (28393993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 747192 + ... + 747229.

It is an arithmetic number, because the mean of its divisors is an integer number (7472110).

Almost surely, 2^28393999 is an apocalyptic number.

28393999 is a deficient number, since it is larger than the sum of its proper divisors (1494441).

28393999 is a wasteful number, since it uses less digits than its factorization.

28393999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494440.

The product of its digits is 944784, while the sum is 52.

The square root of 28393999 is about 5328.6019742518. The cubic root of 28393999 is about 305.0765695064.

It can be divided in two parts, 28393 and 999, that added together give a palindrome (29392).

The spelling of 28393999 in words is "twenty-eight million, three hundred ninety-three thousand, nine hundred ninety-nine".