28172017 has 4 divisors (see below), whose sum is σ = 28318180. Its totient is φ = 28025856.

The previous prime is 28171999. The next prime is 28172051. The reversal of 28172017 is 71027182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71027182 = 2 ⋅35513591.

It can be written as a sum of positive squares in 2 ways, for example, as 7750656 + 20421361 = 2784^2 + 4519^2 .

It is a cyclic number.

It is not a de Polignac number, because 28172017 - 2¹⁵ = 28139249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28172917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72792 + ... + 73177.

It is an arithmetic number, because the mean of its divisors is an integer number (7079545).

Almost surely, 2^28172017 is an apocalyptic number.

It is an amenable number.

28172017 is a deficient number, since it is larger than the sum of its proper divisors (146163).

28172017 is a wasteful number, since it uses less digits than its factorization.

28172017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146162.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 28172017 is about 5307.7318131194. The cubic root of 28172017 is about 304.2794672971.

Adding to 28172017 its reverse (71027182), we get a palindrome (99199199).

The spelling of 28172017 in words is "twenty-eight million, one hundred seventy-two thousand, seventeen".