28187728 has 10 divisors (see below), whose sum is σ = 54613754. Its totient is φ = 14093856.

The previous prime is 28187699. The next prime is 28187729. The reversal of 28187728 is 82778182.

It can be written as a sum of positive squares in only one way, i.e., 26915344 + 1272384 = 5188^2 + 1128^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28187729) 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 as a sum of consecutive naturals, namely, 880851 + ... + 880882.

Almost surely, 2^28187728 is an apocalyptic number.

It is an amenable number.

28187728 is a deficient number, since it is larger than the sum of its proper divisors (26426026).

28187728 is a wasteful number, since it uses less digits than its factorization.

28187728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1761741 (or 1761735 counting only the distinct ones).

The product of its digits is 100352, while the sum is 43.

The square root of 28187728 is about 5309.2116175568. The cubic root of 28187728 is about 304.3360204164.

The spelling of 28187728 in words is "twenty-eight million, one hundred eighty-seven thousand, seven hundred twenty-eight".