21211222101020 has 96 divisors (see below), whose sum is σ = 53608654310400. Its totient is φ = 6886778955264.

The previous prime is 21211222101019. The next prime is 21211222101049. The reversal of 21211222101020 is 2010122211212.

It is a self number, because there is not a number n which added to its sum of digits gives 21211222101020.

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, 4699241 + ... + 8031519.

It is an arithmetic number, because the mean of its divisors is an integer number (558423482400).

Almost surely, 2^{21211222101020} is an apocalyptic number.

21211222101020 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 21211222101020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26804327155200).

21211222101020 is an abundant number, since it is smaller than the sum of its proper divisors (32397432209380).

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

21211222101020 is a wasteful number, since it uses less digits than its factorization.

21211222101020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3334707 (or 3334705 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21211222101020 its reverse (2010122211212), we get a palindrome (23221344312232).

The spelling of 21211222101020 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, one hundred one thousand, twenty".