2001221400 has 48 divisors (see below), whose sum is σ = 6203788200. Its totient is φ = 533658880.

The previous prime is 2001221371. The next prime is 2001221477. The reversal of 2001221400 is 41221002.

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 polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1667085 + ... + 1668284.

Almost surely, 2^2001221400 is an apocalyptic number.

2001221400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001221400 is an abundant number, since it is smaller than the sum of its proper divisors (4202566800).

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

2001221400 is a wasteful number, since it uses less digits than its factorization.

2001221400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3335388 (or 3335379 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2001221400 is about 44735.0131328918. The cubic root of 2001221400 is about 1260.1774756306.

Adding to 2001221400 its reverse (41221002), we get a palindrome (2042442402).

The spelling of 2001221400 in words is "two billion, one million, two hundred twenty-one thousand, four hundred".