28109268 has 108 divisors (see below), whose sum is σ = 81332160. Its totient is φ = 8482320.

The previous prime is 28109251. The next prime is 28109299. The reversal of 28109268 is 86290182.

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 117493 + ... + 117731.

Almost surely, 2^28109268 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28109268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40666080).

28109268 is an abundant number, since it is smaller than the sum of its proper divisors (53222892).

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

28109268 is a wasteful number, since it uses less digits than its factorization.

28109268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 255 counting only the distinct ones).

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

The square root of 28109268 is about 5301.8174242424. The cubic root of 28109268 is about 304.0533868612.

The spelling of 28109268 in words is "twenty-eight million, one hundred nine thousand, two hundred sixty-eight".