212121211021020 has 288 divisors, whose sum is σ = 767418622064640. Its totient is φ = 46371178529280.

The previous prime is 212121211021019. The next prime is 212121211021039. The reversal of 212121211021020 is 20120112121212.

212121211021020 is a `hidden beast` number, since 212 + 1 + 212 + 1 + 10 + 210 + 20 = 666.

212121211021020 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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 = 212121211020984 and 212121211021002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 240412426 + ... + 241293134.

It is an arithmetic number, because the mean of its divisors is an integer number (2664647993280).

Almost surely, 2^{212121211021020} is an apocalyptic number.

212121211021020 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 212121211021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383709311032320).

212121211021020 is an abundant number, since it is smaller than the sum of its proper divisors (555297411043620).

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

212121211021020 is a wasteful number, since it uses less digits than its factorization.

212121211021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889065 (or 889060 counting only the distinct ones).

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

Adding to 212121211021020 its reverse (20120112121212), we get a palindrome (232241323142232).

The spelling of 212121211021020 in words is "two hundred twelve trillion, one hundred twenty-one billion, two hundred eleven million, twenty-one thousand, twenty".