21210220211020 has 48 divisors (see below), whose sum is σ = 45596440834560. Its totient is φ = 8283305451456.

The previous prime is 21210220210999. The next prime is 21210220211027. The reversal of 21210220211020 is 2011202201212.

It is a happy number.

It is a super-2 number, since 2×21210220211020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21210220210985 and 21210220211003.

It is not an unprimeable number, because it can be changed into a prime (21210220211027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3125410 + ... + 7224169.

It is an arithmetic number, because the mean of its divisors is an integer number (949925850720).

Almost surely, 2^{21210220211020} is an apocalyptic number.

21210220211020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210220211020 is an abundant number, since it is smaller than the sum of its proper divisors (24386220623540).

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

21210220211020 is a wasteful number, since it uses less digits than its factorization.

21210220211020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10352014 (or 10352012 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21210220211020 its reverse (2011202201212), we get a palindrome (23221422412232).

The spelling of 21210220211020 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, two hundred eleven thousand, twenty".