28280111 has 8 divisors (see below), whose sum is σ = 29486160. Its totient is φ = 27099072.

The previous prime is 28280107. The next prime is 28280117. The reversal of 28280111 is 11108282.

It is a happy number.

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 28280111 - 2² = 28280107 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 (28280117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3926 + ... + 8483.

It is an arithmetic number, because the mean of its divisors is an integer number (3685770).

Almost surely, 2^28280111 is an apocalyptic number.

28280111 is a deficient number, since it is larger than the sum of its proper divisors (1206049).

28280111 is a wasteful number, since it uses less digits than its factorization.

28280111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12505.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 28280111 is about 5317.9047565747. The cubic root of 28280111 is about 304.6681367541.

Adding to 28280111 its reverse (11108282), we get a palindrome (39388393).

The spelling of 28280111 in words is "twenty-eight million, two hundred eighty thousand, one hundred eleven".