21201002011020 has 192 divisors, whose sum is σ = 64326597963264. Its totient is φ = 5186351462400.

The previous prime is 21201002011009. The next prime is 21201002011051. The reversal of 21201002011020 is 2011020010212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21201002010987 and 21201002011005.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 94938495 + ... + 95161545.

It is an arithmetic number, because the mean of its divisors is an integer number (335034364392).

Almost surely, 2^{21201002011020} is an apocalyptic number.

21201002011020 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 21201002011020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32163298981632).

21201002011020 is an abundant number, since it is smaller than the sum of its proper divisors (43125595952244).

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

21201002011020 is a wasteful number, since it uses less digits than its factorization.

21201002011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223832 (or 223830 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21201002011020 its reverse (2011020010212), we get a palindrome (23212022021232).

The spelling of 21201002011020 in words is "twenty-one trillion, two hundred one billion, two million, eleven thousand, twenty".