212121000020 has 24 divisors (see below), whose sum is σ = 445543991424. Its totient is φ = 84831277856.

The previous prime is 212120999929. The next prime is 212121000029. The reversal of 212121000020 is 20000121212.

It is a happy number.

It is a super-3 number, since 3×212121000020³ (a number of 35 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212120999965 and 212121000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121000029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 968312 + ... + 1166991.

It is an arithmetic number, because the mean of its divisors is an integer number (18564332976).

Almost surely, 2^212121000020 is an apocalyptic number.

212121000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121000020 is an abundant number, since it is smaller than the sum of its proper divisors (233422991404).

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

212121000020 is a wasteful number, since it uses less digits than its factorization.

212121000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2140279 (or 2140277 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 212121000020 its reverse (20000121212), we get a palindrome (232121121232).

The spelling of 212121000020 in words is "two hundred twelve billion, one hundred twenty-one million, twenty", and thus it is an aban number.