28221552 has 60 divisors (see below), whose sum is σ = 82424784. Its totient is φ = 8997120.

The previous prime is 28221551. The next prime is 28221601. The reversal of 28221552 is 25512282.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28221551) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 949 + ... + 7572.

Almost surely, 2^28221552 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 28221552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41212392).

28221552 is an abundant number, since it is smaller than the sum of its proper divisors (54203232).

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

28221552 is a wasteful number, since it uses less digits than its factorization.

28221552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8558 (or 8549 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 28221552 is about 5312.3960695716. The cubic root of 28221552 is about 304.4577015833.

The spelling of 28221552 in words is "twenty-eight million, two hundred twenty-one thousand, five hundred fifty-two".