20000000121221 has 2 divisors, whose sum is σ = 20000000121222. Its totient is φ = 20000000121220.

The previous prime is 20000000121193. The next prime is 20000000121253. The reversal of 20000000121221 is 12212100000002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17122125376321 + 2877874744900 = 4137889^2 + 1696430^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20000000121221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20000000121271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000000060610 + 10000000060611.

It is an arithmetic number, because the mean of its divisors is an integer number (10000000060611).

Almost surely, 2^{20000000121221} is an apocalyptic number.

It is an amenable number.

20000000121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20000000121221 is an equidigital number, since it uses as much as digits as its factorization.

20000000121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20000000121221 its reverse (12212100000002), we get a palindrome (32212100121223).

The spelling of 20000000121221 in words is "twenty trillion, one hundred twenty-one thousand, two hundred twenty-one".