121020110021 has 2 divisors, whose sum is σ = 121020110022. Its totient is φ = 121020110020.

The previous prime is 121020109957. The next prime is 121020110023. The reversal of 121020110021 is 120011020121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88001222500 + 33018887521 = 296650^2 + 181711^2 .

It is a cyclic number.

It is not a de Polignac number, because 121020110021 - 2⁶ = 121020109957 is a prime.

It is a super-3 number, since 3×121020110021³ (a number of 34 digits) contains 333 as substring.

Together with 121020110023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 121020109984 and 121020110011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121020110023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60510055010 + 60510055011.

It is an arithmetic number, because the mean of its divisors is an integer number (60510055011).

Almost surely, 2^121020110021 is an apocalyptic number.

It is an amenable number.

121020110021 is a deficient number, since it is larger than the sum of its proper divisors (1).

121020110021 is an equidigital number, since it uses as much as digits as its factorization.

121020110021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 121020110021 its reverse (120011020121), we get a palindrome (241031130142).

The spelling of 121020110021 in words is "one hundred twenty-one billion, twenty million, one hundred ten thousand, twenty-one".