210121210020 has 192 divisors, whose sum is σ = 606875141376. Its totient is φ = 54302515200.

The previous prime is 210121209997. The next prime is 210121210027. The reversal of 210121210020 is 20012121012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 210121209978 and 210121210005.

It is not an unprimeable number, because it can be changed into a prime (210121210027) 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 63 ways as a sum of consecutive naturals, for example, 60604327 + ... + 60607793.

It is an arithmetic number, because the mean of its divisors is an integer number (3160808028).

Almost surely, 2^210121210020 is an apocalyptic number.

210121210020 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 210121210020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303437570688).

210121210020 is an abundant number, since it is smaller than the sum of its proper divisors (396753931356).

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

210121210020 is a wasteful number, since it uses less digits than its factorization.

210121210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3790 (or 3788 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 210121210020 its reverse (20012121012), we get a palindrome (230133331032).

The spelling of 210121210020 in words is "two hundred ten billion, one hundred twenty-one million, two hundred ten thousand, twenty".