101121021221981 has 2 divisors, whose sum is σ = 101121021221982. Its totient is φ = 101121021221980.

The previous prime is 101121021221933. The next prime is 101121021222007. The reversal of 101121021221981 is 189122120121101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58199733765625 + 42921287456356 = 7628875^2 + 6551434^2 .

It is a cyclic number.

It is not a de Polignac number, because 101121021221981 - 2¹⁸ = 101121020959837 is a prime.

It is a super-2 number, since 2×101121021221981² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101121021221911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50560510610990 + 50560510610991.

It is an arithmetic number, because the mean of its divisors is an integer number (50560510610991).

Almost surely, 2^{101121021221981} is an apocalyptic number.

It is an amenable number.

101121021221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

101121021221981 is an equidigital number, since it uses as much as digits as its factorization.

101121021221981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 32.

The spelling of 101121021221981 in words is "one hundred one trillion, one hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, nine hundred eighty-one".