21220324 has 12 divisors (see below), whose sum is σ = 37179324. Its totient is φ = 10597664.

The previous prime is 21220319. The next prime is 21220327. The reversal of 21220324 is 42302212.

It can be written as a sum of positive squares in 2 ways, for example, as 7022500 + 14197824 = 2650^2 + 3768^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21220298 and 21220307.

It is not an unprimeable number, because it can be changed into a prime (21220327) 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 3 ways as a sum of consecutive naturals, for example, 1434 + ... + 6670.

It is an arithmetic number, because the mean of its divisors is an integer number (3098277).

Almost surely, 2^21220324 is an apocalyptic number.

It is an amenable number.

21220324 is a deficient number, since it is larger than the sum of its proper divisors (15959000).

21220324 is a wasteful number, since it uses less digits than its factorization.

21220324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6254 (or 6252 counting only the distinct ones).

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

The square root of 21220324 is about 4606.5522899453. The cubic root of 21220324 is about 276.8539155949.

Adding to 21220324 its reverse (42302212), we get a palindrome (63522536).

The spelling of 21220324 in words is "twenty-one million, two hundred twenty thousand, three hundred twenty-four".