28513872 has 30 divisors (see below), whose sum is σ = 79799642. Its totient is φ = 9504576.

The previous prime is 28513871. The next prime is 28513883. The reversal of 28513872 is 27831582.

It can be written as a sum of positive squares in only one way, i.e., 28259856 + 254016 = 5316^2 + 504^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28513871) 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 in 5 ways as a sum of consecutive naturals, for example, 98863 + ... + 99150.

Almost surely, 2^28513872 is an apocalyptic number.

It is an amenable number.

28513872 is an abundant number, since it is smaller than the sum of its proper divisors (51285770).

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

28513872 is a wasteful number, since it uses less digits than its factorization.

28513872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198027 (or 198018 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28513872 is about 5339.8381997959. The cubic root of 28513872 is about 305.5052880296.

The spelling of 28513872 in words is "twenty-eight million, five hundred thirteen thousand, eight hundred seventy-two".