21020324 has 24 divisors (see below), whose sum is σ = 39895800. Its totient is φ = 9633024.

The previous prime is 21020303. The next prime is 21020339. The reversal of 21020324 is 42302012.

It can be written as a sum of positive squares in 4 ways, for example, as 2010724 + 19009600 = 1418^2 + 4360^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21020299 and 21020308.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 6392 + ... + 9104.

It is an arithmetic number, because the mean of its divisors is an integer number (1662325).

Almost surely, 2^21020324 is an apocalyptic number.

It is an amenable number.

21020324 is a deficient number, since it is larger than the sum of its proper divisors (18875476).

21020324 is a wasteful number, since it uses less digits than its factorization.

21020324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2879 (or 2877 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21020324 is about 4584.7926888792. The cubic root of 21020324 is about 275.9813927104.

Adding to 21020324 its reverse (42302012), we get a palindrome (63322336).

The spelling of 21020324 in words is "twenty-one million, twenty thousand, three hundred twenty-four".