20121121117021 has 2 divisors, whose sum is σ = 20121121117022. Its totient is φ = 20121121117020.

The previous prime is 20121121116989. The next prime is 20121121117037. The reversal of 20121121117021 is 12071112112102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17503889575225 + 2617231541796 = 4183765^2 + 1617786^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121121117021 - 2⁵ = 20121121116989 is a prime.

It is a super-3 number, since 3×20121121117021³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20121121116983 and 20121121117001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121121117121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060560558510 + 10060560558511.

It is an arithmetic number, because the mean of its divisors is an integer number (10060560558511).

Almost surely, 2^{20121121117021} is an apocalyptic number.

It is an amenable number.

20121121117021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121121117021 is an equidigital number, since it uses as much as digits as its factorization.

20121121117021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 22.

Adding to 20121121117021 its reverse (12071112112102), we get a palindrome (32192233229123).

The spelling of 20121121117021 in words is "twenty trillion, one hundred twenty-one billion, one hundred twenty-one million, one hundred seventeen thousand, twenty-one".