28138799 has 16 divisors (see below), whose sum is σ = 31080000. Its totient is φ = 25318656.

The previous prime is 28138777. The next prime is 28138801. The reversal of 28138799 is 99783182.

It is a cyclic number.

It is not a de Polignac number, because 28138799 - 2⁸ = 28138543 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28138709) 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, 141302 + ... + 141500.

It is an arithmetic number, because the mean of its divisors is an integer number (1942500).

Almost surely, 2^28138799 is an apocalyptic number.

28138799 is a deficient number, since it is larger than the sum of its proper divisors (2941201).

28138799 is a wasteful number, since it uses less digits than its factorization.

28138799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434.

The product of its digits is 217728, while the sum is 47.

The square root of 28138799 is about 5304.6016815591. The cubic root of 28138799 is about 304.1598269390.

The spelling of 28138799 in words is "twenty-eight million, one hundred thirty-eight thousand, seven hundred ninety-nine".