21201110102191 has 2 divisors, whose sum is σ = 21201110102192. Its totient is φ = 21201110102190.

The previous prime is 21201110102177. The next prime is 21201110102213. The reversal of 21201110102191 is 19120101110212.

It is a happy number.

It is an a-pointer prime, because the next prime (21201110102213) can be obtained adding 21201110102191 to its sum of digits (22).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201110102191 - 2¹¹ = 21201110100143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201110105191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600555051095 + 10600555051096.

It is an arithmetic number, because the mean of its divisors is an integer number (10600555051096).

Almost surely, 2^{21201110102191} is an apocalyptic number.

21201110102191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201110102191 is an equidigital number, since it uses as much as digits as its factorization.

21201110102191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 21201110102191 in words is "twenty-one trillion, two hundred one billion, one hundred ten million, one hundred two thousand, one hundred ninety-one".