21043124 has 12 divisors (see below), whose sum is σ = 36864324. Its totient is φ = 10510464.

The previous prime is 21043123. The next prime is 21043129. The reversal of 21043124 is 42134012.

It can be written as a sum of positive squares in 2 ways, for example, as 504100 + 20539024 = 710^2 + 4532^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043123) 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, 2684 + ... + 7020.

It is an arithmetic number, because the mean of its divisors is an integer number (3072027).

Almost surely, 2^21043124 is an apocalyptic number.

It is an amenable number.

21043124 is a deficient number, since it is larger than the sum of its proper divisors (15821200).

21043124 is a wasteful number, since it uses less digits than its factorization.

21043124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5554 (or 5552 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21043124 is about 4587.2784960148. The cubic root of 21043124 is about 276.0811390652.

Adding to 21043124 its reverse (42134012), we get a palindrome (63177136).

It can be divided in two parts, 210 and 43124, that added together give a palindrome (43334).

The spelling of 21043124 in words is "twenty-one million, forty-three thousand, one hundred twenty-four".