2021121002081 has 2 divisors, whose sum is σ = 2021121002082. Its totient is φ = 2021121002080.

The previous prime is 2021121002063. The next prime is 2021121002221. The reversal of 2021121002081 is 1802001211202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1255161715600 + 765959286481 = 1120340^2 + 875191^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021121002081 is a prime.

It is a super-2 number, since 2×2021121002081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2021121002011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010560501040 + 1010560501041.

It is an arithmetic number, because the mean of its divisors is an integer number (1010560501041).

Almost surely, 2^{2021121002081} is an apocalyptic number.

It is an amenable number.

2021121002081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021121002081 is an equidigital number, since it uses as much as digits as its factorization.

2021121002081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 2021121002081 its reverse (1802001211202), we get a palindrome (3823122213283).

The spelling of 2021121002081 in words is "two trillion, twenty-one billion, one hundred twenty-one million, two thousand, eighty-one".