28987311 has 4 divisors (see below), whose sum is σ = 38649752. Its totient is φ = 19324872.

The previous prime is 28987271. The next prime is 28987313. The reversal of 28987311 is 11378982.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28987311 - 2⁷ = 28987183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28987311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28987313) 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 3 ways as a sum of consecutive naturals, for example, 4831216 + ... + 4831221.

It is an arithmetic number, because the mean of its divisors is an integer number (9662438).

Almost surely, 2^28987311 is an apocalyptic number.

28987311 is a deficient number, since it is larger than the sum of its proper divisors (9662441).

28987311 is an equidigital number, since it uses as much as digits as its factorization.

28987311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9662440.

The product of its digits is 24192, while the sum is 39.

The square root of 28987311 is about 5383.9865341585. The cubic root of 28987311 is about 307.1868661140.

The spelling of 28987311 in words is "twenty-eight million, nine hundred eighty-seven thousand, three hundred eleven".