21112211212020 has 72 divisors (see below), whose sum is σ = 64607103045576. Its totient is φ = 5580100657152.

The previous prime is 21112211211997. The next prime is 21112211212031. The reversal of 21112211212020 is 2021211221112.

21112211212020 is a `hidden beast` number, since 211 + 1 + 221 + 1 + 212 + 0 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 17333828964 + 21094877383056 = 131658^2 + 4592916^2 .

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 = 21112211211984 and 21112211212002.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 518962237 + ... + 519002916.

It is an arithmetic number, because the mean of its divisors is an integer number (897320875633).

Almost surely, 2^{21112211212020} is an apocalyptic number.

21112211212020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112211212020 is an abundant number, since it is smaller than the sum of its proper divisors (43494891833556).

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

21112211212020 is a wasteful number, since it uses less digits than its factorization.

21112211212020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1037965281 (or 1037965276 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21112211212020 its reverse (2021211221112), we get a palindrome (23133422433132).

The spelling of 21112211212020 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, two hundred twelve thousand, twenty".