21211212000000 has 2016 divisors, whose sum is σ = 81700189224192. Its totient is φ = 4838400000000.

The previous prime is 21211211999921. The next prime is 21211212000061. The reversal of 21211212000000 is 21211212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21211212000000.

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 223 ways as a sum of consecutive naturals, for example, 210011999950 + ... + 210012000050.

It is an arithmetic number, because the mean of its divisors is an integer number (40525887512).

Almost surely, 2^{21211212000000} is an apocalyptic number.

21211212000000 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 21211212000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40850094612096).

21211212000000 is an abundant number, since it is smaller than the sum of its proper divisors (60488977224192).

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

21211212000000 is an equidigital number, since it uses as much as digits as its factorization.

21211212000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21211212000000 its reverse (21211212), we get a palindrome (21211233211212).

21211212000000 divided by its reverse (21211212) gives a 6-th power (1000000 = 10⁶).

It can be divided in two parts, 2121 and 1212000000, that added together give a palindrome (1212002121).

The spelling of 21211212000000 in words is "twenty-one trillion, two hundred eleven billion, two hundred twelve million", and thus it is an aban number.