20820224 has 36 divisors (see below), whose sum is σ = 41893824. Its totient is φ = 10326528.

The previous prime is 20820211. The next prime is 20820227. The reversal of 20820224 is 42202802.

It is a junction number, because it is equal to n+sod(n) for n = 20820196 and 20820205.

It is not an unprimeable number, because it can be changed into a prime (20820227) 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, 42509 + ... + 42995.

Almost surely, 2^20820224 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 20820224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20946912).

20820224 is an abundant number, since it is smaller than the sum of its proper divisors (21073600).

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

20820224 is an equidigital number, since it uses as much as digits as its factorization.

20820224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670 (or 656 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 20820224 is about 4562.9183643804. The cubic root of 20820224 is about 275.1028772114.

The spelling of 20820224 in words is "twenty million, eight hundred twenty thousand, two hundred twenty-four".