2100001221200 has 60 divisors (see below), whose sum is σ = 5342032535580. Its totient is φ = 790588692480.

The previous prime is 2100001221193. The next prime is 2100001221271. The reversal of 2100001221200 is 21221000012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 29464409104 + 2070536812096 = 171652^2 + 1438936^2 .

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, 154405055 + ... + 154418654.

It is an arithmetic number, because the mean of its divisors is an integer number (89033875593).

Almost surely, 2^{2100001221200} is an apocalyptic number.

2100001221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100001221200 is an abundant number, since it is smaller than the sum of its proper divisors (3242031314380).

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

2100001221200 is a wasteful number, since it uses less digits than its factorization.

2100001221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308823744 (or 308823733 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 2100001221200 its reverse (21221000012), we get a palindrome (2121222221212).

The spelling of 2100001221200 in words is "two trillion, one hundred billion, one million, two hundred twenty-one thousand, two hundred".