101020111121981 has 2 divisors, whose sum is σ = 101020111121982. Its totient is φ = 101020111121980.

The previous prime is 101020111121933. The next prime is 101020111121999. The reversal of 101020111121981 is 189121111020101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92684712744100 + 8335398377881 = 9627290^2 + 2887109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101020111121981 is a prime.

It is a super-2 number, since 2×101020111121981² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101020111121911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50510055560990 + 50510055560991.

It is an arithmetic number, because the mean of its divisors is an integer number (50510055560991).

Almost surely, 2^{101020111121981} is an apocalyptic number.

It is an amenable number.

101020111121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

101020111121981 is an equidigital number, since it uses as much as digits as its factorization.

101020111121981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 29.

The spelling of 101020111121981 in words is "one hundred one trillion, twenty billion, one hundred eleven million, one hundred twenty-one thousand, nine hundred eighty-one".