21839028 has 48 divisors (see below), whose sum is σ = 52961664. Its totient is φ = 6998400.

The previous prime is 21839023. The next prime is 21839053. The reversal of 21839028 is 82093812.

It is a self number, because there is not a number n which added to its sum of digits gives 21839028.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21839023) 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 in 15 ways as a sum of consecutive naturals, for example, 44601 + ... + 45087.

It is an arithmetic number, because the mean of its divisors is an integer number (1103368).

Almost surely, 2^21839028 is an apocalyptic number.

It is an amenable number.

21839028 is an abundant number, since it is smaller than the sum of its proper divisors (31122636).

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

21839028 is a wasteful number, since it uses less digits than its factorization.

21839028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 630 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 21839028 is about 4673.2245826624. The cubic root of 21839028 is about 279.5188505415.

It can be divided in two parts, 2183 and 9028, that added together give a palindrome (11211).

The spelling of 21839028 in words is "twenty-one million, eight hundred thirty-nine thousand, twenty-eight".