28221608 has 16 divisors (see below), whose sum is σ = 52977780. Its totient is φ = 14094208.

The previous prime is 28221607. The next prime is 28221617. The reversal of 28221608 is 80612282.

It can be written as a sum of positive squares in 2 ways, for example, as 27478564 + 743044 = 5242^2 + 862^2 .

It is not an unprimeable number, because it can be changed into a prime (28221601) 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 3 ways as a sum of consecutive naturals, for example, 8066 + ... + 11022.

Almost surely, 2^28221608 is an apocalyptic number.

It is an amenable number.

28221608 is a deficient number, since it is larger than the sum of its proper divisors (24756172).

28221608 is a wasteful number, since it uses less digits than its factorization.

28221608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4156 (or 4152 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 28221608 is about 5312.4013402604. The cubic root of 28221608 is about 304.4579029615.

The spelling of 28221608 in words is "twenty-eight million, two hundred twenty-one thousand, six hundred eight".