2101121220 has 192 divisors, whose sum is σ = 6649574400. Its totient is φ = 491235840.

The previous prime is 2101121207. The next prime is 2101121237. The reversal of 2101121220 is 221211012.

It is a super-2 number, since 2×2101121220² = 8829420762268576800, which contains 22 as substring.

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 = 2101121196 and 2101121205.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3394071 + ... + 3394689.

It is an arithmetic number, because the mean of its divisors is an integer number (34633200).

Almost surely, 2^2101121220 is an apocalyptic number.

2101121220 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 2101121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3324787200).

2101121220 is an abundant number, since it is smaller than the sum of its proper divisors (4548453180).

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

2101121220 is a wasteful number, since it uses less digits than its factorization.

2101121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818 (or 816 counting only the distinct ones).

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

The square root of 2101121220 is about 45837.9888302268. The cubic root of 2101121220 is about 1280.8070309421.

Adding to 2101121220 its reverse (221211012), we get a palindrome (2322332232).

It can be divided in two parts, 2101 and 121220, that added together give a palindrome (123321).

The spelling of 2101121220 in words is "two billion, one hundred one million, one hundred twenty-one thousand, two hundred twenty".