28491328 has 28 divisors (see below), whose sum is σ = 56748172. Its totient is φ = 14192640.

The previous prime is 28491301. The next prime is 28491329. The reversal of 28491328 is 82319482.

It can be written as a sum of positive squares in 2 ways, for example, as 18045504 + 10445824 = 4248^2 + 3232^2 .

It is not an unprimeable number, because it can be changed into a prime (28491329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20908 + ... + 22228.

Almost surely, 2^28491328 is an apocalyptic number.

It is an amenable number.

28491328 is a deficient number, since it is larger than the sum of its proper divisors (28256844).

28491328 is a wasteful number, since it uses less digits than its factorization.

28491328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1670 (or 1660 counting only the distinct ones).

The product of its digits is 27648, while the sum is 37.

The square root of 28491328 is about 5337.7268570057. The cubic root of 28491328 is about 305.4247526429.

The spelling of 28491328 in words is "twenty-eight million, four hundred ninety-one thousand, three hundred twenty-eight".