28318220 has 48 divisors (see below), whose sum is σ = 69000960. Its totient is φ = 9561024.

The previous prime is 28318217. The next prime is 28318229. The reversal of 28318220 is 2281382.

It is a self number, because there is not a number n which added to its sum of digits gives 28318220.

It is not an unprimeable number, because it can be changed into a prime (28318229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7871 + ... + 10889.

It is an arithmetic number, because the mean of its divisors is an integer number (1437520).

Almost surely, 2^28318220 is an apocalyptic number.

28318220 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 28318220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34500480).

28318220 is an abundant number, since it is smaller than the sum of its proper divisors (40682740).

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

28318220 is a wasteful number, since it uses less digits than its factorization.

28318220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3102 (or 3100 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 28318220 is about 5321.4866343908. The cubic root of 28318220 is about 304.8049276672.

The spelling of 28318220 in words is "twenty-eight million, three hundred eighteen thousand, two hundred twenty".