28505219 has 2 divisors, whose sum is σ = 28505220. Its totient is φ = 28505218.

The previous prime is 28505177. The next prime is 28505237. The reversal of 28505219 is 91250582.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28505219 - 2²⁰ = 27456643 is a prime.

It is a super-4 number, since 4×28505219⁴ (a number of 31 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28505249) 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, 14252609 + 14252610.

It is an arithmetic number, because the mean of its divisors is an integer number (14252610).

Almost surely, 2^28505219 is an apocalyptic number.

28505219 is a deficient number, since it is larger than the sum of its proper divisors (1).

28505219 is an equidigital number, since it uses as much as digits as its factorization.

28505219 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 28505219 is about 5339.0279077750. The cubic root of 28505219 is about 305.4743813805.

The spelling of 28505219 in words is "twenty-eight million, five hundred five thousand, two hundred nineteen".