2001101220 has 96 divisors (see below), whose sum is σ = 6232262400. Its totient is φ = 533060352.

The previous prime is 2001101209. The next prime is 2001101257. The reversal of 2001101220 is 221011002.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 840672 + ... + 843048.

It is an arithmetic number, because the mean of its divisors is an integer number (64919400).

Almost surely, 2^2001101220 is an apocalyptic number.

2001101220 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 2001101220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3116131200).

2001101220 is an abundant number, since it is smaller than the sum of its proper divisors (4231161180).

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

2001101220 is a wasteful number, since it uses less digits than its factorization.

2001101220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3954 (or 3946 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 2001101220 is about 44733.6698695736. The cubic root of 2001101220 is about 1260.1522491763.

Adding to 2001101220 its reverse (221011002), we get a palindrome (2222112222).

The spelling of 2001101220 in words is "two billion, one million, one hundred one thousand, two hundred twenty".