21212322020 has 48 divisors (see below), whose sum is σ = 46153981440. Its totient is φ = 8179538304.

The previous prime is 21212322013. The next prime is 21212322059. The reversal of 21212322020 is 2022321212.

It is a self number, because there is not a number n which added to its sum of digits gives 21212322020.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 346997 + ... + 403523.

It is an arithmetic number, because the mean of its divisors is an integer number (961541280).

Almost surely, 2^21212322020 is an apocalyptic number.

21212322020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212322020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23076990720).

21212322020 is an abundant number, since it is smaller than the sum of its proper divisors (24941659420).

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

21212322020 is a wasteful number, since it uses less digits than its factorization.

21212322020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57212 (or 57210 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21212322020 its reverse (2022321212), we get a palindrome (23234643232).

The spelling of 21212322020 in words is "twenty-one billion, two hundred twelve million, three hundred twenty-two thousand, twenty".