21010020020120 has 128 divisors (see below), whose sum is σ = 48173413340160. Its totient is φ = 8244905518080.

The previous prime is 21010020020111. The next prime is 21010020020161. The reversal of 21010020020120 is 2102002001012.

It is a happy number.

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, 1767472817 + ... + 1767484703.

It is an arithmetic number, because the mean of its divisors is an integer number (376354791720).

Almost surely, 2^{21010020020120} is an apocalyptic number.

21010020020120 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 21010020020120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24086706670080).

21010020020120 is an abundant number, since it is smaller than the sum of its proper divisors (27163393320040).

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

21010020020120 is a wasteful number, since it uses less digits than its factorization.

21010020020120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14593 (or 14589 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21010020020120 its reverse (2102002001012), we get a palindrome (23112022021132).

The spelling of 21010020020120 in words is "twenty-one trillion, ten billion, twenty million, twenty thousand, one hundred twenty".