21212002021200 has 120 divisors (see below), whose sum is σ = 67950276493248. Its totient is φ = 5656437027840.

The previous prime is 21212002021139. The next prime is 21212002021207. The reversal of 21212002021200 is 212020021212.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21212002021200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212002021207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 94763812 + ... + 94987388.

Almost surely, 2^{21212002021200} is an apocalyptic number.

21212002021200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212002021200 is an abundant number, since it is smaller than the sum of its proper divisors (46738274472048).

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

21212002021200 is a wasteful number, since it uses less digits than its factorization.

21212002021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302661 (or 302650 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21212002021200 its reverse (212020021212), we get a palindrome (21424022042412).

The spelling of 21212002021200 in words is "twenty-one trillion, two hundred twelve billion, two million, twenty-one thousand, two hundred".