28307219 has 12 divisors (see below), whose sum is σ = 29704584. Its totient is φ = 26971392.

The previous prime is 28307189. The next prime is 28307231. The reversal of 28307219 is 91270382.

It is not a de Polignac number, because 28307219 - 2⁸ = 28306963 is a prime.

It is a super-2 number, since 2×28307219² = 1602597295027922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28307249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81404 + ... + 81750.

It is an arithmetic number, because the mean of its divisors is an integer number (2475382).

Almost surely, 2^28307219 is an apocalyptic number.

28307219 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28307219 is a deficient number, since it is larger than the sum of its proper divisors (1397365).

28307219 is an equidigital number, since it uses as much as digits as its factorization.

28307219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 28307219 is about 5320.4528942563. The cubic root of 28307219 is about 304.7654525718.

The spelling of 28307219 in words is "twenty-eight million, three hundred seven thousand, two hundred nineteen".