28191304 has 32 divisors (see below), whose sum is σ = 56571480. Its totient is φ = 13123584.

The previous prime is 28191301. The next prime is 28191323. The reversal of 28191304 is 40319182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20340100 + 7851204 = 4510^2 + 2802^2 .

It is not an unprimeable number, because it can be changed into a prime (28191301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12124 + ... + 14260.

Almost surely, 2^28191304 is an apocalyptic number.

It is an amenable number.

28191304 is an abundant number, since it is smaller than the sum of its proper divisors (28380176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28191304 is a wasteful number, since it uses less digits than its factorization.

28191304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2257 (or 2253 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 28191304 is about 5309.5483800414. The cubic root of 28191304 is about 304.3488896053.

The spelling of 28191304 in words is "twenty-eight million, one hundred ninety-one thousand, three hundred four".