2001221200 has 60 divisors (see below), whose sum is σ = 5245030368. Its totient is φ = 727715200.

The previous prime is 2001221141. The next prime is 2001221203. The reversal of 2001221200 is 21221002.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 223012 + ... + 231811.

Almost surely, 2^2001221200 is an apocalyptic number.

2001221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001221200 is an abundant number, since it is smaller than the sum of its proper divisors (3243809168).

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

2001221200 is a wasteful number, since it uses less digits than its factorization.

2001221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454852 (or 454841 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 2001221200 is about 44735.0108975062. The cubic root of 2001221200 is about 1260.1774336503.

Adding to 2001221200 its reverse (21221002), we get a palindrome (2022442202).

The spelling of 2001221200 in words is "two billion, one million, two hundred twenty-one thousand, two hundred".