28281109 has 8 divisors (see below), whose sum is σ = 28575360. Its totient is φ = 27988800.

The previous prime is 28281091. The next prime is 28281151. The reversal of 28281109 is 90118282.

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 28281109 - 2¹⁷ = 28150037 is a prime.

It is a super-2 number, since 2×28281109² = 1599642252539762, 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 (28281809) 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, 57354 + ... + 57844.

It is an arithmetic number, because the mean of its divisors is an integer number (3571920).

Almost surely, 2^28281109 is an apocalyptic number.

It is an amenable number.

28281109 is a deficient number, since it is larger than the sum of its proper divisors (294251).

28281109 is a wasteful number, since it uses less digits than its factorization.

28281109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 971.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 28281109 is about 5317.9985896952. The cubic root of 28281109 is about 304.6717206064.

The spelling of 28281109 in words is "twenty-eight million, two hundred eighty-one thousand, one hundred nine".