21722324 has 12 divisors (see below), whose sum is σ = 40938324. Its totient is φ = 10025664.

The previous prime is 21722321. The next prime is 21722341. The reversal of 21722324 is 42322712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 3489424 + 18232900 = 1868^2 + 4270^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21722324.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722321) 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, 208817 + ... + 208920.

It is an arithmetic number, because the mean of its divisors is an integer number (3411527).

Almost surely, 2^21722324 is an apocalyptic number.

It is an amenable number.

21722324 is a deficient number, since it is larger than the sum of its proper divisors (19216000).

21722324 is a wasteful number, since it uses less digits than its factorization.

21722324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417754 (or 417752 counting only the distinct ones).

The product of its digits is 1344, while the sum is 23.

The square root of 21722324 is about 4660.7214033881. The cubic root of 21722324 is about 279.0200608212.

The spelling of 21722324 in words is "twenty-one million, seven hundred twenty-two thousand, three hundred twenty-four".