20121121100221 has 2 divisors, whose sum is σ = 20121121100222. Its totient is φ = 20121121100220.

The previous prime is 20121121100207. The next prime is 20121121100239. The reversal of 20121121100221 is 12200112112102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12360779324100 + 7760341776121 = 3515790^2 + 2785739^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121121100221 - 2²⁹ = 20120584229309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121121100195 and 20121121100204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121121100021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060560550110 + 10060560550111.

It is an arithmetic number, because the mean of its divisors is an integer number (10060560550111).

Almost surely, 2^{20121121100221} is an apocalyptic number.

It is an amenable number.

20121121100221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121121100221 is an equidigital number, since it uses as much as digits as its factorization.

20121121100221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20121121100221 its reverse (12200112112102), we get a palindrome (32321233212323).

The spelling of 20121121100221 in words is "twenty trillion, one hundred twenty-one billion, one hundred twenty-one million, one hundred thousand, two hundred twenty-one".