28021232 has 10 divisors (see below), whose sum is σ = 54291168. Its totient is φ = 14010608.

The previous prime is 28021207. The next prime is 28021237. The reversal of 28021232 is 23212082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28021237) by changing a digit.

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 as a sum of consecutive naturals, namely, 875648 + ... + 875679.

Almost surely, 2^28021232 is an apocalyptic number.

It is an amenable number.

28021232 is a deficient number, since it is larger than the sum of its proper divisors (26269936).

28021232 is a wasteful number, since it uses less digits than its factorization.

28021232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751335 (or 1751329 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 28021232 is about 5293.5084773711. The cubic root of 28021232 is about 303.7356311967.

It can be divided in two parts, 280 and 21232, that added together give a palindrome (21512).

The spelling of 28021232 in words is "twenty-eight million, twenty-one thousand, two hundred thirty-two".