2102121220 has 48 divisors (see below), whose sum is σ = 4535169408. Its totient is φ = 818012160.

The previous prime is 2102121169. The next prime is 2102121223. The reversal of 2102121220 is 221212012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2102121220.

It is not an unprimeable number, because it can be changed into a prime (2102121223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216265 + ... + 225775.

It is an arithmetic number, because the mean of its divisors is an integer number (94482696).

Almost surely, 2^2102121220 is an apocalyptic number.

2102121220 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 2102121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2267584704).

2102121220 is an abundant number, since it is smaller than the sum of its proper divisors (2433048188).

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

2102121220 is a wasteful number, since it uses less digits than its factorization.

2102121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9820 (or 9818 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2102121220 is about 45848.8955155956. The cubic root of 2102121220 is about 1281.0101929298.

Adding to 2102121220 its reverse (221212012), we get a palindrome (2323333232).

The spelling of 2102121220 in words is "two billion, one hundred two million, one hundred twenty-one thousand, two hundred twenty".