28211717 has 2 divisors, whose sum is σ = 28211718. Its totient is φ = 28211716.

The previous prime is 28211683. The next prime is 28211749. The reversal of 28211717 is 71711282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28153636 + 58081 = 5306^2 + 241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28211717 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28211717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28214717) 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 as a sum of consecutive naturals, namely, 14105858 + 14105859.

It is an arithmetic number, because the mean of its divisors is an integer number (14105859).

Almost surely, 2^28211717 is an apocalyptic number.

It is an amenable number.

28211717 is a deficient number, since it is larger than the sum of its proper divisors (1).

28211717 is an equidigital number, since it uses as much as digits as its factorization.

28211717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1568, while the sum is 29.

The square root of 28211717 is about 5311.4703237428. The cubic root of 28211717 is about 304.4223303961.

Adding to 28211717 its reverse (71711282), we get a palindrome (99922999).

The spelling of 28211717 in words is "twenty-eight million, two hundred eleven thousand, seven hundred seventeen".