28281930 has 32 divisors (see below), whose sum is σ = 68192064. Its totient is φ = 7506816.

The previous prime is 28281907. The next prime is 28281971. The reversal of 28281930 is 3918282.

It is a junction number, because it is equal to n+sod(n) for n = 28281891 and 28281900.

It is an unprimeable number.

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, 4734 + ... + 8886.

It is an arithmetic number, because the mean of its divisors is an integer number (2131002).

Almost surely, 2^28281930 is an apocalyptic number.

28281930 is an abundant number, since it is smaller than the sum of its proper divisors (39910134).

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

28281930 is a wasteful number, since it uses less digits than its factorization.

28281930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4390.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 28281930 is about 5318.0757798286. The cubic root of 28281930 is about 304.6746687825.

The spelling of 28281930 in words is "twenty-eight million, two hundred eighty-one thousand, nine hundred thirty".