28781105 has 8 divisors (see below), whose sum is σ = 36355200. Its totient is φ = 21812976.

The previous prime is 28781101. The next prime is 28781141. The reversal of 28781105 is 50118782.

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 28781105 - 2² = 28781101 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28781101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151385 + ... + 151574.

It is an arithmetic number, because the mean of its divisors is an integer number (4544400).

Almost surely, 2^28781105 is an apocalyptic number.

It is an amenable number.

28781105 is a deficient number, since it is larger than the sum of its proper divisors (7574095).

28781105 is a wasteful number, since it uses less digits than its factorization.

28781105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302983.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 28781105 is about 5364.8024194746. The cubic root of 28781105 is about 306.4567239555.

Adding to 28781105 its reverse (50118782), we get a palindrome (78899887).

The spelling of 28781105 in words is "twenty-eight million, seven hundred eighty-one thousand, one hundred five".