28111290 has 64 divisors (see below), whose sum is σ = 71165952. Its totient is φ = 7092800.

The previous prime is 28111271. The next prime is 28111331. The reversal of 28111290 is 9211182.

It is a self number, because there is not a number n which added to its sum of digits gives 28111290.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90235 + ... + 90545.

It is an arithmetic number, because the mean of its divisors is an integer number (1111968).

Almost surely, 2^28111290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28111290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35582976).

28111290 is an abundant number, since it is smaller than the sum of its proper divisors (43054662).

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

28111290 is a wasteful number, since it uses less digits than its factorization.

28111290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 28111290 is about 5302.0081101409. The cubic root of 28111290 is about 304.0606772350.

The spelling of 28111290 in words is "twenty-eight million, one hundred eleven thousand, two hundred ninety".