20643224 has 32 divisors (see below), whose sum is σ = 44388000. Its totient is φ = 8816640.

The previous prime is 20643223. The next prime is 20643229. The reversal of 20643224 is 42234602.

It is a super-2 number, since 2×20643224² = 852285394228352, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20643224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24734 + ... + 25554.

It is an arithmetic number, because the mean of its divisors is an integer number (1387125).

Almost surely, 2^20643224 is an apocalyptic number.

It is an amenable number.

20643224 is an abundant number, since it is smaller than the sum of its proper divisors (23744776).

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

20643224 is a wasteful number, since it uses less digits than its factorization.

20643224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283 (or 1279 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 20643224 is about 4543.4814845006. The cubic root of 20643224 is about 274.3210756534.

Adding to 20643224 its reverse (42234602), we get a palindrome (62877826).

The spelling of 20643224 in words is "twenty million, six hundred forty-three thousand, two hundred twenty-four".