210121220212020 has 240 divisors, whose sum is σ = 711059627733840. Its totient is φ = 51634922287104.

The previous prime is 210121220211953. The next prime is 210121220212021. The reversal of 210121220212020 is 20212022121012.

It is a happy number.

210121220212020 is a `hidden beast` number, since 210 + 1 + 2 + 1 + 220 + 212 + 0 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 6507213253776 + 203614006958244 = 2550924^2 + 14269338^2 .

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 = 210121220211984 and 210121220212002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121220212021) 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 79 ways as a sum of consecutive naturals, for example, 4076046 + ... + 20901114.

It is an arithmetic number, because the mean of its divisors is an integer number (2962748448891).

Almost surely, 2^{210121220212020} is an apocalyptic number.

210121220212020 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 210121220212020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355529813866920).

210121220212020 is an abundant number, since it is smaller than the sum of its proper divisors (500938407521820).

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

210121220212020 is a wasteful number, since it uses less digits than its factorization.

210121220212020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16825696 (or 16825685 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 210121220212020 its reverse (20212022121012), we get a palindrome (230333242333032).

The spelling of 210121220212020 in words is "two hundred ten trillion, one hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, twenty".