20004224 has 32 divisors (see below), whose sum is σ = 40190040. Its totient is φ = 9917440.

The previous prime is 20004221. The next prime is 20004233. The reversal of 20004224 is 42240002.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 20004199 and 20004208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20004221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16172 + ... + 17364.

Almost surely, 2^20004224 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 20004224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20095020).

20004224 is an abundant number, since it is smaller than the sum of its proper divisors (20185816).

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

20004224 is a wasteful number, since it uses less digits than its factorization.

20004224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1338 (or 1326 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 20004224 is about 4472.6081876239. The cubic root of 20004224 is about 271.4608698144.

Adding to 20004224 its reverse (42240002), we get a palindrome (62244226).

The spelling of 20004224 in words is "twenty million, four thousand, two hundred twenty-four".