28187219 has 2 divisors, whose sum is σ = 28187220. Its totient is φ = 28187218.

The previous prime is 28187209. The next prime is 28187233. The reversal of 28187219 is 91278182.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28187219 is a prime.

It is a super-2 number, since 2×28187219² = 1589038629907922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28187209) 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, 14093609 + 14093610.

It is an arithmetic number, because the mean of its divisors is an integer number (14093610).

Almost surely, 2^28187219 is an apocalyptic number.

28187219 is a deficient number, since it is larger than the sum of its proper divisors (1).

28187219 is an equidigital number, since it uses as much as digits as its factorization.

28187219 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 38.

The square root of 28187219 is about 5309.1636817864. The cubic root of 28187219 is about 304.3341885557.

The spelling of 28187219 in words is "twenty-eight million, one hundred eighty-seven thousand, two hundred nineteen".