28109517 has 16 divisors (see below), whose sum is σ = 39866112. Its totient is φ = 17556480.

The previous prime is 28109509. The next prime is 28109537. The reversal of 28109517 is 71590182.

It is not a de Polignac number, because 28109517 - 2³ = 28109509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28109537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11148 + ... + 13434.

It is an arithmetic number, because the mean of its divisors is an integer number (2491632).

Almost surely, 2^28109517 is an apocalyptic number.

It is an amenable number.

28109517 is a deficient number, since it is larger than the sum of its proper divisors (11756595).

28109517 is a wasteful number, since it uses less digits than its factorization.

28109517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2548.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 28109517 is about 5301.8409067040. The cubic root of 28109517 is about 304.0542846561.

Adding to 28109517 its reverse (71590182), we get a palindrome (99699699).

The spelling of 28109517 in words is "twenty-eight million, one hundred nine thousand, five hundred seventeen".