2001121211100 has 144 divisors (see below), whose sum is σ = 6339071523456. Its totient is φ = 483368736000.

The previous prime is 2001121211093. The next prime is 2001121211113. The reversal of 2001121211100 is 11121211002.

It is a super-2 number, since 2×2001121211100² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 180486 + ... + 2008685.

It is an arithmetic number, because the mean of its divisors is an integer number (44021330024).

Almost surely, 2^{2001121211100} is an apocalyptic number.

2001121211100 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 2001121211100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3169535761728).

2001121211100 is an abundant number, since it is smaller than the sum of its proper divisors (4337950312356).

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

2001121211100 is a wasteful number, since it uses less digits than its factorization.

2001121211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2189476 (or 2189469 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 2001121211100 its reverse (11121211002), we get a palindrome (2012242422102).

The spelling of 2001121211100 in words is "two trillion, one billion, one hundred twenty-one million, two hundred eleven thousand, one hundred".