21204322 has 4 divisors (see below), whose sum is σ = 31806486. Its totient is φ = 10602160.

The previous prime is 21204251. The next prime is 21204329. The reversal of 21204322 is 22340212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 10764961 + 10439361 = 3281^2 + 3231^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21204296 and 21204305.

It is not an unprimeable number, because it can be changed into a prime (21204329) 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 as a sum of consecutive naturals, namely, 5301079 + ... + 5301082.

Almost surely, 2^21204322 is an apocalyptic number.

21204322 is a deficient number, since it is larger than the sum of its proper divisors (10602164).

21204322 is a wasteful number, since it uses less digits than its factorization.

21204322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10602163.

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

The square root of 21204322 is about 4604.8150885785. The cubic root of 21204322 is about 276.7843073203.

Adding to 21204322 its reverse (22340212), we get a palindrome (43544534).

The spelling of 21204322 in words is "twenty-one million, two hundred four thousand, three hundred twenty-two".