28243215 has 192 divisors, whose sum is σ = 71500800. Its totient is φ = 10264320.

The previous prime is 28243213. The next prime is 28243231. The reversal of 28243215 is 51234282.

It is not a de Polignac number, because 28243215 - 2¹ = 28243213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28243213) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1486476 + ... + 1486494.

It is an arithmetic number, because the mean of its divisors is an integer number (372400).

Almost surely, 2^28243215 is an apocalyptic number.

28243215 is an abundant number, since it is smaller than the sum of its proper divisors (43257585).

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

28243215 is a wasteful number, since it uses less digits than its factorization.

28243215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 58 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 28243215 is about 5314.4345889285. The cubic root of 28243215 is about 304.5355827281.

Adding to 28243215 its reverse (51234282), we get a palindrome (79477497).

The spelling of 28243215 in words is "twenty-eight million, two hundred forty-three thousand, two hundred fifteen".