28391272 has 64 divisors (see below), whose sum is σ = 66729600. Its totient is φ = 11024640.

The previous prime is 28391249. The next prime is 28391281. The reversal of 28391272 is 27219382.

It is a congruent number.

It is an unprimeable number.

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, 42622 + ... + 43282.

It is an arithmetic number, because the mean of its divisors is an integer number (1042650).

Almost surely, 2^28391272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28391272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33364800).

28391272 is an abundant number, since it is smaller than the sum of its proper divisors (38338328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28391272 is a wasteful number, since it uses less digits than its factorization.

28391272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 742 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The square root of 28391272 is about 5328.3460848560. The cubic root of 28391272 is about 305.0668025314.

The spelling of 28391272 in words is "twenty-eight million, three hundred ninety-one thousand, two hundred seventy-two".