21021201110191 has 2 divisors, whose sum is σ = 21021201110192. Its totient is φ = 21021201110190.

The previous prime is 21021201110153. The next prime is 21021201110233. The reversal of 21021201110191 is 19101110212012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021201110191 is a prime.

It is a super-2 number, since 2×21021201110191² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021201510191) 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, 10510600555095 + 10510600555096.

It is an arithmetic number, because the mean of its divisors is an integer number (10510600555096).

Almost surely, 2^{21021201110191} is an apocalyptic number.

21021201110191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021201110191 is an equidigital number, since it uses as much as digits as its factorization.

21021201110191 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 21021201110191 in words is "twenty-one trillion, twenty-one billion, two hundred one million, one hundred ten thousand, one hundred ninety-one".