28220544 has 192 divisors, whose sum is σ = 94517280. Its totient is φ = 7987200.

The previous prime is 28220519. The next prime is 28220551. The reversal of 28220544 is 44502282.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 215359 + ... + 215489.

Almost surely, 2^28220544 is an apocalyptic number.

28220544 is a gapful number since it is divisible by the number (24) 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 28220544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47258640).

28220544 is an abundant number, since it is smaller than the sum of its proper divisors (66296736).

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

28220544 is a wasteful number, since it uses less digits than its factorization.

28220544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

The square root of 28220544 is about 5312.3011962802. The cubic root of 28220544 is about 304.4540767293.

The spelling of 28220544 in words is "twenty-eight million, two hundred twenty thousand, five hundred forty-four".