1020121120021 has 2 divisors, whose sum is σ = 1020121120022. Its totient is φ = 1020121120020.

The previous prime is 1020121120013. The next prime is 1020121120027. The reversal of 1020121120021 is 1200211210201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 764949648996 + 255171471025 = 874614^2 + 505145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020121120021 - 2³ = 1020121120013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1020121119983 and 1020121120010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1020121120027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510060560010 + 510060560011.

It is an arithmetic number, because the mean of its divisors is an integer number (510060560011).

Almost surely, 2^{1020121120021} is an apocalyptic number.

It is an amenable number.

1020121120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020121120021 is an equidigital number, since it uses as much as digits as its factorization.

1020121120021 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 13.

Adding to 1020121120021 its reverse (1200211210201), we get a palindrome (2220332330222).

The spelling of 1020121120021 in words is "one trillion, twenty billion, one hundred twenty-one million, one hundred twenty thousand, twenty-one".