28220000 has 120 divisors (see below), whose sum is σ = 74394936. Its totient is φ = 10496000.

The previous prime is 28219999. The next prime is 28220021. The reversal of 28220000 is 2282.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 339959 + ... + 340041.

Almost surely, 2^28220000 is an apocalyptic number.

28220000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37197468).

28220000 is an abundant number, since it is smaller than the sum of its proper divisors (46174936).

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

28220000 is an equidigital number, since it uses as much as digits as its factorization.

28220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 28220000 is about 5312.2499941174. The cubic root of 28220000 is about 304.4521204230.

Adding to 28220000 its reverse (2282), we get a palindrome (28222282).

The spelling of 28220000 in words is "twenty-eight million, two hundred twenty thousand".