20121221021201 has 2 divisors, whose sum is σ = 20121221021202. Its totient is φ = 20121221021200.

The previous prime is 20121221021159. The next prime is 20121221021203. The reversal of 20121221021201 is 10212012212102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10807005334801 + 9314215686400 = 3287401^2 + 3051920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20121221021201 is a prime.

It is a Sophie Germain prime.

Together with 20121221021203, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121221021201.

It is not a weakly prime, because it can be changed into another prime (20121221021203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060610510600 + 10060610510601.

It is an arithmetic number, because the mean of its divisors is an integer number (10060610510601).

Almost surely, 2^{20121221021201} is an apocalyptic number.

It is an amenable number.

20121221021201 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121221021201 is an equidigital number, since it uses as much as digits as its factorization.

20121221021201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20121221021201 its reverse (10212012212102), we get a palindrome (30333233233303).

The spelling of 20121221021201 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, twenty-one thousand, two hundred one".