28887911 has 4 divisors (see below), whose sum is σ = 31110072. Its totient is φ = 26665752.

The previous prime is 28887907. The next prime is 28887917. The reversal of 28887911 is 11978882.

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

It is a cyclic number.

It is not a de Polignac number, because 28887911 - 2² = 28887907 is a prime.

It is a super-2 number, since 2×28887911² = 1669022803887842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28887917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111061 + ... + 1111086.

It is an arithmetic number, because the mean of its divisors is an integer number (7777518).

Almost surely, 2^28887911 is an apocalyptic number.

28887911 is a deficient number, since it is larger than the sum of its proper divisors (2222161).

28887911 is a wasteful number, since it uses less digits than its factorization.

28887911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2222160.

The product of its digits is 64512, while the sum is 44.

The square root of 28887911 is about 5374.7475289543. The cubic root of 28887911 is about 306.8353405470.

The spelling of 28887911 in words is "twenty-eight million, eight hundred eighty-seven thousand, nine hundred eleven".