2001212221100 has 72 divisors (see below), whose sum is σ = 4369396538640. Its totient is φ = 795554599680.

The previous prime is 2001212221061. The next prime is 2001212221121. The reversal of 2001212221100 is 11222121002.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48471266 + ... + 48512534.

Almost surely, 2^{2001212221100} is an apocalyptic number.

2001212221100 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 2001212221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2184698269320).

2001212221100 is an abundant number, since it is smaller than the sum of its proper divisors (2368184317540).

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

2001212221100 is a wasteful number, since it uses less digits than its factorization.

2001212221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44259 (or 44252 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2001212221100 its reverse (11222121002), we get a palindrome (2012434342102).

The spelling of 2001212221100 in words is "two trillion, one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred".