201021111091 has 2 divisors, whose sum is σ = 201021111092. Its totient is φ = 201021111090.

The previous prime is 201021110993. The next prime is 201021111113. The reversal of 201021111091 is 190111120102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201021111091 - 2¹¹ = 201021109043 is a prime.

It is not a weakly prime, because it can be changed into another prime (201021111691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510555545 + 100510555546.

It is an arithmetic number, because the mean of its divisors is an integer number (100510555546).

Almost surely, 2^201021111091 is an apocalyptic number.

201021111091 is a deficient number, since it is larger than the sum of its proper divisors (1).

201021111091 is an equidigital number, since it uses as much as digits as its factorization.

201021111091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 19.

Adding to 201021111091 its reverse (190111120102), we get a palindrome (391132231193).

The spelling of 201021111091 in words is "two hundred one billion, twenty-one million, one hundred eleven thousand, ninety-one".