21210220012020 has 96 divisors (see below), whose sum is σ = 63959481772032. Its totient is φ = 5220772282368.

The previous prime is 21210220011961. The next prime is 21210220012021. The reversal of 21210220012020 is 2021002201212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220012021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19847469 + ... + 20888811.

It is an arithmetic number, because the mean of its divisors is an integer number (666244601792).

Almost surely, 2^{21210220012020} is an apocalyptic number.

21210220012020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210220012020 is an abundant number, since it is smaller than the sum of its proper divisors (42749261760012).

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

21210220012020 is a wasteful number, since it uses less digits than its factorization.

21210220012020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067481 (or 1067479 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21210220012020 its reverse (2021002201212), we get a palindrome (23231222213232).

The spelling of 21210220012020 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, twelve thousand, twenty".