21010122120020 has 96 divisors (see below), whose sum is σ = 48477404102400. Its totient is φ = 7585450767360.

The previous prime is 21010122120011. The next prime is 21010122120037. The reversal of 21010122120020 is 2002122101012.

It is a junction number, because it is equal to n+sod(n) for n = 21010122119977 and 21010122120004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17302529 + ... + 18476951.

It is an arithmetic number, because the mean of its divisors is an integer number (504972959400).

Almost surely, 2^{21010122120020} is an apocalyptic number.

21010122120020 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 21010122120020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24238702051200).

21010122120020 is an abundant number, since it is smaller than the sum of its proper divisors (27467281982380).

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

21010122120020 is a wasteful number, since it uses less digits than its factorization.

21010122120020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1175025 (or 1175023 counting only the distinct ones).

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

Adding to 21010122120020 its reverse (2002122101012), we get a palindrome (23012244221032).

The spelling of 21010122120020 in words is "twenty-one trillion, ten billion, one hundred twenty-two million, one hundred twenty thousand, twenty".