28138563 has 16 divisors (see below), whose sum is σ = 43881600. Its totient is φ = 17771400.

The previous prime is 28138549. The next prime is 28138573. The reversal of 28138563 is 36583182.

It is not a de Polignac number, because 28138563 - 2⁴ = 28138547 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (28138543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26913 + ... + 27938.

It is an arithmetic number, because the mean of its divisors is an integer number (2742600).

Almost surely, 2^28138563 is an apocalyptic number.

28138563 is a deficient number, since it is larger than the sum of its proper divisors (15743037).

28138563 is a wasteful number, since it uses less digits than its factorization.

28138563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54879 (or 54873 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 28138563 is about 5304.5794366754. The cubic root of 28138563 is about 304.1589766076.

The spelling of 28138563 in words is "twenty-eight million, one hundred thirty-eight thousand, five hundred sixty-three".