21020131221100 has 288 divisors, whose sum is σ = 51138980770752. Its totient is φ = 7434892800000.

The previous prime is 21020131221097. The next prime is 21020131221101. The reversal of 21020131221100 is 112213102012.

It is not an unprimeable number, because it can be changed into a prime (21020131221101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8220621022 + ... + 8220623578.

It is an arithmetic number, because the mean of its divisors is an integer number (177565905454).

Almost surely, 2^{21020131221100} is an apocalyptic number.

21020131221100 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 21020131221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25569490385376).

21020131221100 is an abundant number, since it is smaller than the sum of its proper divisors (30118849549652).

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

21020131221100 is a wasteful number, since it uses less digits than its factorization.

21020131221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3957 (or 3950 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21020131221100 its reverse (112213102012), we get a palindrome (21132344323112).

The spelling of 21020131221100 in words is "twenty-one trillion, twenty billion, one hundred thirty-one million, two hundred twenty-one thousand, one hundred".