28021824 has 42 divisors (see below), whose sum is σ = 80321150. Its totient is φ = 9340416.

The previous prime is 28021813. The next prime is 28021837. The reversal of 28021824 is 42812082.

It can be written as a sum of positive squares in only one way, i.e., 23040000 + 4981824 = 4800^2 + 2232^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23749 + ... + 24900.

Almost surely, 2^28021824 is an apocalyptic number.

28021824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28021824 is an abundant number, since it is smaller than the sum of its proper divisors (52299326).

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

28021824 is a wasteful number, since it uses less digits than its factorization.

28021824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48667 (or 48654 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 28021824 is about 5293.5643946211. The cubic root of 28021824 is about 303.7377701726.

The spelling of 28021824 in words is "twenty-eight million, twenty-one thousand, eight hundred twenty-four".