28216530 has 24 divisors (see below), whose sum is σ = 73363212. Its totient is φ = 7524384.

The previous prime is 28216519. The next prime is 28216547. The reversal of 28216530 is 3561282.

28216530 is a `hidden beast` number, since 2 + 8 + 2 + 1 + 653 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 27594009 + 622521 = 5253^2 + 789^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28216494 and 28216503.

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 11 ways as a sum of consecutive naturals, for example, 156669 + ... + 156848.

Almost surely, 2^28216530 is an apocalyptic number.

28216530 is an abundant number, since it is smaller than the sum of its proper divisors (45146682).

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

28216530 is a wasteful number, since it uses less digits than its factorization.

28216530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313530 (or 313527 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 28216530 is about 5311.9233804715. The cubic root of 28216530 is about 304.4396411865.

The spelling of 28216530 in words is "twenty-eight million, two hundred sixteen thousand, five hundred thirty".