28239222 has 48 divisors (see below), whose sum is σ = 62876016. Its totient is φ = 8448000.

The previous prime is 28239209. The next prime is 28239259. The reversal of 28239222 is 22293282.

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

It is a self number, because there is not a number n which added to its sum of digits gives 28239222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70222 + ... + 70622.

It is an arithmetic number, because the mean of its divisors is an integer number (1309917).

Almost surely, 2^28239222 is an apocalyptic number.

28239222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 28239222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31438008).

28239222 is an abundant number, since it is smaller than the sum of its proper divisors (34636794).

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

28239222 is a wasteful number, since it uses less digits than its factorization.

28239222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 514 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 28239222 is about 5314.0589006898. The cubic root of 28239222 is about 304.5212303973.

The spelling of 28239222 in words is "twenty-eight million, two hundred thirty-nine thousand, two hundred twenty-two".