201020111121989 has 2 divisors, whose sum is σ = 201020111121990. Its totient is φ = 201020111121988.

The previous prime is 201020111121979. The next prime is 201020111122093. The reversal of 201020111121989 is 989121111020102.

201020111121989 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., 168491225493889 + 32528885628100 = 12980417^2 + 5703410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201020111121989 is a prime.

It is a super-2 number, since 2×201020111121989² (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 (201020111121979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510055560994 + 100510055560995.

It is an arithmetic number, because the mean of its divisors is an integer number (100510055560995).

Almost surely, 2^{201020111121989} is an apocalyptic number.

It is an amenable number.

201020111121989 is a deficient number, since it is larger than the sum of its proper divisors (1).

201020111121989 is an equidigital number, since it uses as much as digits as its factorization.

201020111121989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 38.

The spelling of 201020111121989 in words is "two hundred one trillion, twenty billion, one hundred eleven million, one hundred twenty-one thousand, nine hundred eighty-nine".