21210210120020 has 48 divisors (see below), whose sum is σ = 45456439533120. Its totient is φ = 8310814907136.

The previous prime is 21210210119977. The next prime is 21210210120089. The reversal of 21210210120020 is 2002101201212.

It is a junction number, because it is equal to n+sod(n) for n = 21210210119977 and 21210210120004.

It is a congruent number.

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, 31423577 + ... + 32091456.

It is an arithmetic number, because the mean of its divisors is an integer number (947009156940).

Almost surely, 2^{21210210120020} is an apocalyptic number.

21210210120020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210210120020 is an abundant number, since it is smaller than the sum of its proper divisors (24246229413100).

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

21210210120020 is a wasteful number, since it uses less digits than its factorization.

21210210120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63515384 (or 63515382 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21210210120020 its reverse (2002101201212), we get a palindrome (23212311321232).

The spelling of 21210210120020 in words is "twenty-one trillion, two hundred ten billion, two hundred ten million, one hundred twenty thousand, twenty".