21021222020 has 24 divisors (see below), whose sum is σ = 44147472768. Its totient is φ = 8407935200.

The previous prime is 21021221999. The next prime is 21021222031. The reversal of 21021222020 is 2022212012.

It is a junction number, because it is equal to n+sod(n) for n = 21021221986 and 21021222004.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 426875 + ... + 473565.

It is an arithmetic number, because the mean of its divisors is an integer number (1839478032).

Almost surely, 2^21021222020 is an apocalyptic number.

21021222020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021222020 is an abundant number, since it is smaller than the sum of its proper divisors (23126250748).

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

21021222020 is a wasteful number, since it uses less digits than its factorization.

21021222020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69211 (or 69209 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21021222020 its reverse (2022212012), we get a palindrome (23043434032).

It can be divided in two parts, 210212 and 22020, that added together give a palindrome (232232).

The spelling of 21021222020 in words is "twenty-one billion, twenty-one million, two hundred twenty-two thousand, twenty".