21212001221000 has 128 divisors (see below), whose sum is σ = 49776007057920. Its totient is φ = 8460900000000.

The previous prime is 21212001220997. The next prime is 21212001221003. The reversal of 21212001221000 is 12210021212.

21212001221000 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (21212001220997) and next prime (21212001221003).

It is not an unprimeable number, because it can be changed into a prime (21212001221003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1073961125 + ... + 1073980875.

It is an arithmetic number, because the mean of its divisors is an integer number (388875055140).

Almost surely, 2^{21212001221000} is an apocalyptic number.

21212001221000 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 21212001221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24888003528960).

21212001221000 is an abundant number, since it is smaller than the sum of its proper divisors (28564005836920).

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

21212001221000 is a wasteful number, since it uses less digits than its factorization.

21212001221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22744 (or 22730 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21212001221000 its reverse (12210021212), we get a palindrome (21224211242212).

The spelling of 21212001221000 in words is "twenty-one trillion, two hundred twelve billion, one million, two hundred twenty-one thousand".