10101021221981 has 2 divisors, whose sum is σ = 10101021221982. Its totient is φ = 10101021221980.

The previous prime is 10101021221959. The next prime is 10101021222011. The reversal of 10101021221981 is 18912212010101.

10101021221981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6295658083225 + 3805363138756 = 2509115^2 + 1950734^2 .

It is a cyclic number.

It is not a de Polignac number, because 10101021221981 - 2³⁴ = 10083841352797 is a prime.

It is a super-2 number, since 2×10101021221981² (a number of 27 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 (10101021221281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5050510610990 + 5050510610991.

It is an arithmetic number, because the mean of its divisors is an integer number (5050510610991).

Almost surely, 2^{10101021221981} is an apocalyptic number.

It is an amenable number.

10101021221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10101021221981 is an equidigital number, since it uses as much as digits as its factorization.

10101021221981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 29.

The spelling of 10101021221981 in words is "ten trillion, one hundred one billion, twenty-one million, two hundred twenty-one thousand, nine hundred eighty-one".