28407217 has 2 divisors, whose sum is σ = 28407218. Its totient is φ = 28407216.

The previous prime is 28407199. The next prime is 28407227. The reversal of 28407217 is 71270482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24443136 + 3964081 = 4944^2 + 1991^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28407217 is a prime.

It is not a weakly prime, because it can be changed into another prime (28407227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14203608 + 14203609.

It is an arithmetic number, because the mean of its divisors is an integer number (14203609).

Almost surely, 2^28407217 is an apocalyptic number.

It is an amenable number.

28407217 is a deficient number, since it is larger than the sum of its proper divisors (1).

28407217 is an equidigital number, since it uses as much as digits as its factorization.

28407217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 28407217 is about 5329.8421177367. The cubic root of 28407217 is about 305.1239020023.

Adding to 28407217 its reverse (71270482), we get a palindrome (99677699).

It can be divided in two parts, 284072 and 17, that added together give a square (284089 = 533²).

The spelling of 28407217 in words is "twenty-eight million, four hundred seven thousand, two hundred seventeen".