28142217 has 12 divisors (see below), whose sum is σ = 40724164. Its totient is φ = 18727200.

The previous prime is 28142183. The next prime is 28142227. The reversal of 28142217 is 71224182.

It can be written as a sum of positive squares in 2 ways, for example, as 41616 + 28100601 = 204^2 + 5301^2 .

It is not a de Polignac number, because 28142217 - 2⁸ = 28141961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28142227) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2967 + ... + 8067.

Almost surely, 2^28142217 is an apocalyptic number.

It is an amenable number.

28142217 is a deficient number, since it is larger than the sum of its proper divisors (12581947).

28142217 is a wasteful number, since it uses less digits than its factorization.

28142217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5720 (or 5717 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 28142217 is about 5304.9238448822. The cubic root of 28142217 is about 304.1721418001.

Adding to 28142217 its reverse (71224182), we get a palindrome (99366399).

The spelling of 28142217 in words is "twenty-eight million, one hundred forty-two thousand, two hundred seventeen".