2121001200 has 180 divisors, whose sum is σ = 7633422888. Its totient is φ = 565574400.

The previous prime is 2121001193. The next prime is 2121001213. The reversal of 2121001200 is 21001212.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 86290 + ... + 108110.

Almost surely, 2^2121001200 is an apocalyptic number.

2121001200 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 2121001200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3816711444).

2121001200 is an abundant number, since it is smaller than the sum of its proper divisors (5512421688).

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

2121001200 is a wasteful number, since it uses less digits than its factorization.

2121001200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21854 (or 21831 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 2121001200 is about 46054.3287867710. The cubic root of 2121001200 is about 1284.8338543788.

Adding to 2121001200 its reverse (21001212), we get a palindrome (2142002412).

The spelling of 2121001200 in words is "two billion, one hundred twenty-one million, one thousand, two hundred".