28221048 has 64 divisors (see below), whose sum is σ = 79408800. Its totient is φ = 9401184.

The previous prime is 28220999. The next prime is 28221049. The reversal of 28221048 is 84012282.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28221049) 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, 16690 + ... + 18302.

Almost surely, 2^28221048 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 28221048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39704400).

28221048 is an abundant number, since it is smaller than the sum of its proper divisors (51187752).

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

28221048 is an equidigital number, since it uses as much as digits as its factorization.

28221048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640 (or 1618 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 28221048 is about 5312.3486331377. The cubic root of 28221048 is about 304.4558891671.

The spelling of 28221048 in words is "twenty-eight million, two hundred twenty-one thousand, forty-eight".