28123543 has 4 divisors (see below), whose sum is σ = 32141200. Its totient is φ = 24105888.

The previous prime is 28123519. The next prime is 28123561. The reversal of 28123543 is 34532182.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28123543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28123573) 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 3 ways as a sum of consecutive naturals, for example, 2008818 + ... + 2008831.

It is an arithmetic number, because the mean of its divisors is an integer number (8035300).

Almost surely, 2^28123543 is an apocalyptic number.

28123543 is a deficient number, since it is larger than the sum of its proper divisors (4017657).

28123543 is an equidigital number, since it uses as much as digits as its factorization.

28123543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4017656.

The product of its digits is 5760, while the sum is 28.

The square root of 28123543 is about 5303.1634898426. The cubic root of 28123543 is about 304.1048482697.

The spelling of 28123543 in words is "twenty-eight million, one hundred twenty-three thousand, five hundred forty-three".