28221060 has 144 divisors (see below), whose sum is σ = 95376960. Its totient is φ = 6209280.

The previous prime is 28221049. The next prime is 28221077. The reversal of 28221060 is 6012282.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 85095 + ... + 85425.

It is an arithmetic number, because the mean of its divisors is an integer number (662340).

Almost surely, 2^28221060 is an apocalyptic number.

28221060 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 28221060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47688480).

28221060 is an abundant number, since it is smaller than the sum of its proper divisors (67155900).

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

28221060 is a wasteful number, since it uses less digits than its factorization.

28221060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 28221060 is about 5312.3497625815. The cubic root of 28221060 is about 304.4559323201.

The spelling of 28221060 in words is "twenty-eight million, two hundred twenty-one thousand, sixty".