28005311 has 8 divisors (see below), whose sum is σ = 28626048. Its totient is φ = 27391000.

The previous prime is 28005269. The next prime is 28005317. The reversal of 28005311 is 11350082.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28005311 - 2⁶ = 28005247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28005317) 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 7 ways as a sum of consecutive naturals, for example, 7796 + ... + 10806.

It is an arithmetic number, because the mean of its divisors is an integer number (3578256).

Almost surely, 2^28005311 is an apocalyptic number.

28005311 is a deficient number, since it is larger than the sum of its proper divisors (620737).

28005311 is a wasteful number, since it uses less digits than its factorization.

28005311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3213.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 28005311 is about 5292.0044406633. The cubic root of 28005311 is about 303.6780951691.

Adding to 28005311 its reverse (11350082), we get a palindrome (39355393).

The spelling of 28005311 in words is "twenty-eight million, five thousand, three hundred eleven".