2021111020081 has 2 divisors, whose sum is σ = 2021111020082. Its totient is φ = 2021111020080.

The previous prime is 2021111020067. The next prime is 2021111020151. The reversal of 2021111020081 is 1800201111202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1993235712400 + 27875307681 = 1411820^2 + 166959^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021111020081 - 2¹⁷ = 2021110889009 is a prime.

It is a super-2 number, since 2×2021111020081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2021111020681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010555510040 + 1010555510041.

It is an arithmetic number, because the mean of its divisors is an integer number (1010555510041).

Almost surely, 2^{2021111020081} is an apocalyptic number.

It is an amenable number.

2021111020081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021111020081 is an equidigital number, since it uses as much as digits as its factorization.

2021111020081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 2021111020081 its reverse (1800201111202), we get a palindrome (3821312131283).

The spelling of 2021111020081 in words is "two trillion, twenty-one billion, one hundred eleven million, twenty thousand, eighty-one".