28112215 has 4 divisors (see below), whose sum is σ = 33734664. Its totient is φ = 22489768.

The previous prime is 28112209. The next prime is 28112221. The reversal of 28112215 is 51221182.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28112209) and next prime (28112221).

It is a cyclic number.

It is not a de Polignac number, because 28112215 - 2⁷ = 28112087 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 2811217 + ... + 2811226.

It is an arithmetic number, because the mean of its divisors is an integer number (8433666).

Almost surely, 2^28112215 is an apocalyptic number.

28112215 is a deficient number, since it is larger than the sum of its proper divisors (5622449).

28112215 is an equidigital number, since it uses as much as digits as its factorization.

28112215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5622448.

The product of its digits is 320, while the sum is 22.

The square root of 28112215 is about 5302.0953405234. The cubic root of 28112215 is about 304.0640122301.

Adding to 28112215 its reverse (51221182), we get a palindrome (79333397).

The spelling of 28112215 in words is "twenty-eight million, one hundred twelve thousand, two hundred fifteen".