28109028 has 12 divisors (see below), whose sum is σ = 65587760. Its totient is φ = 9369672.

The previous prime is 28109023. The next prime is 28109047. The reversal of 28109028 is 82090182.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28108986 and 28109004.

It is not an unprimeable number, because it can be changed into a prime (28109021) 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 3 ways as a sum of consecutive naturals, for example, 1171198 + ... + 1171221.

Almost surely, 2^28109028 is an apocalyptic number.

It is an amenable number.

28109028 is an abundant number, since it is smaller than the sum of its proper divisors (37478732).

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

28109028 is a wasteful number, since it uses less digits than its factorization.

28109028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2342426 (or 2342424 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 28109028 is about 5301.7947904460. The cubic root of 28109028 is about 304.0525215118.

The spelling of 28109028 in words is "twenty-eight million, one hundred nine thousand, twenty-eight".