20101121021 has 2 divisors, whose sum is σ = 20101121022. Its totient is φ = 20101121020.

The previous prime is 20101120979. The next prime is 20101121063. The reversal of 20101121021 is 12012110102.

It is a balanced prime because it is at equal distance from previous prime (20101120979) and next prime (20101121063).

It can be written as a sum of positive squares in only one way, i.e., 16289416900 + 3811704121 = 127630^2 + 61739^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101121021 - 2³⁰ = 19027379197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20101120993 and 20101121011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20101121081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050560510 + 10050560511.

It is an arithmetic number, because the mean of its divisors is an integer number (10050560511).

Almost surely, 2^20101121021 is an apocalyptic number.

It is an amenable number.

20101121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101121021 is an equidigital number, since it uses as much as digits as its factorization.

20101121021 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20101121021 its reverse (12012110102), we get a palindrome (32113231123).

The spelling of 20101121021 in words is "twenty billion, one hundred one million, one hundred twenty-one thousand, twenty-one".