21121020212020 has 12 divisors (see below), whose sum is σ = 44354142445284. Its totient is φ = 8448408084800.

The previous prime is 21121020211979. The next prime is 21121020212023. The reversal of 21121020212020 is 2021202012112.

It is a happy number.

21121020212020 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 11213898848656 + 9907121363364 = 3348716^2 + 3147558^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21121020211985 and 21121020212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121020212023) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 528025505281 + ... + 528025505320.

It is an arithmetic number, because the mean of its divisors is an integer number (3696178537107).

Almost surely, 2^{21121020212020} is an apocalyptic number.

21121020212020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121020212020 is an abundant number, since it is smaller than the sum of its proper divisors (23233122233264).

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

21121020212020 is a wasteful number, since it uses less digits than its factorization.

21121020212020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056051010610 (or 1056051010608 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21121020212020 its reverse (2021202012112), we get a palindrome (23142222224132).

The spelling of 21121020212020 in words is "twenty-one trillion, one hundred twenty-one billion, twenty million, two hundred twelve thousand, twenty".