28281906 has 32 divisors (see below), whose sum is σ = 63794880. Its totient is φ = 9285408.

The previous prime is 28281901. The next prime is 28281907. The reversal of 28281906 is 60918282.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28281901) 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 15 ways as a sum of consecutive naturals, for example, 291 + ... + 7526.

It is an arithmetic number, because the mean of its divisors is an integer number (1993590).

Almost surely, 2^28281906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28281906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31897440).

28281906 is an abundant number, since it is smaller than the sum of its proper divisors (35512974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28281906 is a wasteful number, since it uses less digits than its factorization.

28281906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7895 (or 7889 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 28281906 is about 5318.0735233729. The cubic root of 28281906 is about 304.6745826003.

The spelling of 28281906 in words is "twenty-eight million, two hundred eighty-one thousand, nine hundred six".