28313217 has 6 divisors (see below), whose sum is σ = 40896882. Its totient is φ = 18875472.

The previous prime is 28313203. The next prime is 28313227. The reversal of 28313217 is 71231382.

It can be written as a sum of positive squares in only one way, i.e., 28259856 + 53361 = 5316^2 + 231^2 .

It is not a de Polignac number, because 28313217 - 2¹² = 28309121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28313227) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1572948 + ... + 1572965.

It is an arithmetic number, because the mean of its divisors is an integer number (6816147).

Almost surely, 2^28313217 is an apocalyptic number.

It is an amenable number.

28313217 is a deficient number, since it is larger than the sum of its proper divisors (12583665).

28313217 is a wasteful number, since it uses less digits than its factorization.

28313217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3145919 (or 3145916 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 28313217 is about 5321.0165382190. The cubic root of 28313217 is about 304.7869765758.

Adding to 28313217 its reverse (71231382), we get a palindrome (99544599).

The spelling of 28313217 in words is "twenty-eight million, three hundred thirteen thousand, two hundred seventeen".