21211112012020 has 144 divisors (see below), whose sum is σ = 52382217379968. Its totient is φ = 7193019590400.

The previous prime is 21211112012009. The next prime is 21211112012107. The reversal of 21211112012020 is 2021021111212.

It is a super-2 number, since 2×21211112012020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21211112011985 and 21211112012003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 97188339 + ... + 97406341.

It is an arithmetic number, because the mean of its divisors is an integer number (363765398472).

Almost surely, 2^{21211112012020} is an apocalyptic number.

21211112012020 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 21211112012020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26191108689984).

21211112012020 is an abundant number, since it is smaller than the sum of its proper divisors (31171105367948).

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

21211112012020 is a wasteful number, since it uses less digits than its factorization.

21211112012020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219110 (or 219101 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21211112012020 its reverse (2021021111212), we get a palindrome (23232133123232).

The spelling of 21211112012020 in words is "twenty-one trillion, two hundred eleven billion, one hundred twelve million, twelve thousand, twenty".