2100212121220 has 24 divisors (see below), whose sum is σ = 4437503409024. Its totient is φ = 834930952416.

The previous prime is 2100212121191. The next prime is 2100212121221. The reversal of 2100212121220 is 221212120012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 2100212121194 and 2100212121203.

It is not an unprimeable number, because it can be changed into a prime (2100212121221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322115164 + ... + 322121683.

It is an arithmetic number, because the mean of its divisors is an integer number (184895975376).

Almost surely, 2^{2100212121220} is an apocalyptic number.

2100212121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100212121220 is an abundant number, since it is smaller than the sum of its proper divisors (2337291287804).

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

2100212121220 is a wasteful number, since it uses less digits than its factorization.

2100212121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644237019 (or 644237017 counting only the distinct ones).

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

Adding to 2100212121220 its reverse (221212120012), we get a palindrome (2321424241232).

The spelling of 2100212121220 in words is "two trillion, one hundred billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty".