28215872 has 28 divisors (see below), whose sum is σ = 57361836. Its totient is φ = 13762560.

The previous prime is 28215851. The next prime is 28215899. The reversal of 28215872 is 27851282.

It can be written as a sum of positive squares in 2 ways, for example, as 13957696 + 14258176 = 3736^2 + 3776^2 .

It is a super-2 number, since 2×28215872² = 1592270865440768, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2753 + ... + 8000.

It is an arithmetic number, because the mean of its divisors is an integer number (2048637).

Almost surely, 2^28215872 is an apocalyptic number.

It is an amenable number.

28215872 is an abundant number, since it is smaller than the sum of its proper divisors (29145964).

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

28215872 is a wasteful number, since it uses less digits than its factorization.

28215872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10806 (or 10796 counting only the distinct ones).

The product of its digits is 17920, while the sum is 35.

The square root of 28215872 is about 5311.8614439761. The cubic root of 28215872 is about 304.4372746914.

The spelling of 28215872 in words is "twenty-eight million, two hundred fifteen thousand, eight hundred seventy-two".