20121221210000 has 100 divisors (see below), whose sum is σ = 48719220143484. Its totient is φ = 8047872000000.

The previous prime is 20121221209997. The next prime is 20121221210029. The reversal of 20121221210000 is 1212212102.

It can be written as a sum of positive squares in 10 ways, for example, as 4994348918416 + 15126872291584 = 2234804^2 + 3889328^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 143940140 + ... + 144079860.

Almost surely, 2^{20121221210000} is an apocalyptic number.

20121221210000 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 20121221210000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24359610071742).

20121221210000 is an abundant number, since it is smaller than the sum of its proper divisors (28597998933484).

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

20121221210000 is a wasteful number, since it uses less digits than its factorization.

20121221210000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154150 (or 154129 counting only the distinct ones).

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

Adding to 20121221210000 its reverse (1212212102), we get a palindrome (20122433422102).

The spelling of 20121221210000 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred ten thousand".