21423324 has 48 divisors (see below), whose sum is σ = 54190080. Its totient is φ = 6548160.

The previous prime is 21423319. The next prime is 21423343. The reversal of 21423324 is 42332412.

It is a super-2 number, since 2×21423324² = 917917622417952, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21423324.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 29437 + ... + 30155.

It is an arithmetic number, because the mean of its divisors is an integer number (1128960).

Almost surely, 2^21423324 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21423324, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27095040).

21423324 is an abundant number, since it is smaller than the sum of its proper divisors (32766756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21423324 is a wasteful number, since it uses less digits than its factorization.

21423324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930 (or 928 counting only the distinct ones).

The product of its digits is 1152, while the sum is 21.

The square root of 21423324 is about 4628.5336770947. The cubic root of 21423324 is about 277.7339379466.

Adding to 21423324 its reverse (42332412), we get a palindrome (63755736).

The spelling of 21423324 in words is "twenty-one million, four hundred twenty-three thousand, three hundred twenty-four".