21211221022020 has 288 divisors, whose sum is σ = 65002405104000. Its totient is φ = 5598518446080.

The previous prime is 21211221022003. The next prime is 21211221022021. The reversal of 21211221022020 is 2022012211212.

It is a happy number.

21211221022020 is a `hidden beast` number, since 2 + 1 + 211 + 2 + 210 + 220 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21211221021984 and 21211221022002.

It is not an unprimeable number, because it can be changed into a prime (21211221022021) 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, 7025908071 + ... + 7025911089.

It is an arithmetic number, because the mean of its divisors is an integer number (225702795500).

Almost surely, 2^{21211221022020} is an apocalyptic number.

21211221022020 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 21211221022020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32501202552000).

21211221022020 is an abundant number, since it is smaller than the sum of its proper divisors (43791184081980).

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

21211221022020 is a wasteful number, since it uses less digits than its factorization.

21211221022020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4163 (or 4158 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21211221022020 its reverse (2022012211212), we get a palindrome (23233233233232).

The spelling of 21211221022020 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, twenty-two thousand, twenty".