20423443220 has 12 divisors (see below), whose sum is σ = 42889230804. Its totient is φ = 8169377280.

The previous prime is 20423443213. The next prime is 20423443231. The reversal of 20423443220 is 2234432402.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4623456016 + 15799987204 = 67996^2 + 125698^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20423443220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510586061 + ... + 510586100.

It is an arithmetic number, because the mean of its divisors is an integer number (3574102567).

Almost surely, 2^20423443220 is an apocalyptic number.

20423443220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20423443220 is an abundant number, since it is smaller than the sum of its proper divisors (22465787584).

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

20423443220 is a wasteful number, since it uses less digits than its factorization.

20423443220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021172170 (or 1021172168 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 26.

Adding to 20423443220 its reverse (2234432402), we get a palindrome (22657875622).

The spelling of 20423443220 in words is "twenty billion, four hundred twenty-three million, four hundred forty-three thousand, two hundred twenty".