21043024 has 20 divisors (see below), whose sum is σ = 41035444. Its totient is φ = 10453248.

The previous prime is 21043021. The next prime is 21043027. The reversal of 21043024 is 42034012.

It is an interprime number because it is at equal distance from previous prime (21043021) and next prime (21043027).

It can be written as a sum of positive squares in 2 ways, for example, as 4494400 + 16548624 = 2120^2 + 4068^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21042989 and 21043007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1677 + ... + 6700.

Almost surely, 2^21043024 is an apocalyptic number.

It is an amenable number.

21043024 is a deficient number, since it is larger than the sum of its proper divisors (19992420).

21043024 is a wasteful number, since it uses less digits than its factorization.

21043024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8542 (or 8536 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21043024 is about 4587.2675962930. The cubic root of 21043024 is about 276.0807017385.

Adding to 21043024 its reverse (42034012), we get a palindrome (63077036).

It can be divided in two parts, 210 and 43024, that added together give a palindrome (43234).

The spelling of 21043024 in words is "twenty-one million, forty-three thousand, twenty-four".