2001021100 has 72 divisors (see below), whose sum is σ = 4922410640. Its totient is φ = 699943680.

The previous prime is 2001021097. The next prime is 2001021101. The reversal of 2001021100 is 11201002.

It is not an unprimeable number, because it can be changed into a prime (2001021101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15807 + ... + 65206.

Almost surely, 2^2001021100 is an apocalyptic number.

2001021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001021100 is an abundant number, since it is smaller than the sum of its proper divisors (2921389540).

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

2001021100 is a wasteful number, since it uses less digits than its factorization.

2001021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81059 (or 81052 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 2001021100 is about 44732.7743382858. The cubic root of 2001021100 is about 1260.1354309789.

Adding to 2001021100 its reverse (11201002), we get a palindrome (2012222102).

The spelling of 2001021100 in words is "two billion, one million, twenty-one thousand, one hundred".