2001221121200 has 120 divisors (see below), whose sum is σ = 5545193105760. Its totient is φ = 679838054400.

The previous prime is 2001221121199. The next prime is 2001221121203. The reversal of 2001221121200 is 21211221002.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is not an unprimeable number, because it can be changed into a prime (2001221121203) 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, 2973341 + ... + 3583740.

It is an arithmetic number, because the mean of its divisors is an integer number (46209942548).

Almost surely, 2^{2001221121200} is an apocalyptic number.

2001221121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001221121200 is an abundant number, since it is smaller than the sum of its proper divisors (3543971984560).

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

2001221121200 is a wasteful number, since it uses less digits than its factorization.

2001221121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6557215 (or 6557204 counting only the distinct ones).

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

Adding to 2001221121200 its reverse (21211221002), we get a palindrome (2022432342202).

The spelling of 2001221121200 in words is "two trillion, one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred".