21211021211200 has 168 divisors, whose sum is σ = 53774684418920. Its totient is φ = 8230997606400.

The previous prime is 21211021211183. The next prime is 21211021211209. The reversal of 21211021211200 is 211212011212.

It can be written as a sum of positive squares in 12 ways, for example, as 3718819123776 + 17492202087424 = 1928424^2 + 4182368^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21211021211209) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 5636266 + ... + 8613334.

Almost surely, 2^{21211021211200} is an apocalyptic number.

21211021211200 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 21211021211200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26887342209460).

21211021211200 is an abundant number, since it is smaller than the sum of its proper divisors (32563663207720).

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

21211021211200 is a wasteful number, since it uses less digits than its factorization.

21211021211200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2977225 (or 2977210 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21211021211200 its reverse (211212011212), we get a palindrome (21422233222412).

The spelling of 21211021211200 in words is "twenty-one trillion, two hundred eleven billion, twenty-one million, two hundred eleven thousand, two hundred".