21001201122020 has 96 divisors (see below), whose sum is σ = 50660182003200. Its totient is φ = 7163660528640.

The previous prime is 21001201122001. The next prime is 21001201122023. The reversal of 21001201122020 is 2022110210012.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21001201121986 and 21001201122004.

It is not an unprimeable number, because it can be changed into a prime (21001201122023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 503158592 + ... + 503200328.

It is an arithmetic number, because the mean of its divisors is an integer number (527710229200).

Almost surely, 2^{21001201122020} is an apocalyptic number.

21001201122020 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 21001201122020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25330091001600).

21001201122020 is an abundant number, since it is smaller than the sum of its proper divisors (29658980881180).

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

21001201122020 is a wasteful number, since it uses less digits than its factorization.

21001201122020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60013 (or 60011 counting only the distinct ones).

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

Adding to 21001201122020 its reverse (2022110210012), we get a palindrome (23023311332032).

The spelling of 21001201122020 in words is "twenty-one trillion, one billion, two hundred one million, one hundred twenty-two thousand, twenty".