21102110191 has 2 divisors, whose sum is σ = 21102110192. Its totient is φ = 21102110190.

The previous prime is 21102110177. The next prime is 21102110203. The reversal of 21102110191 is 19101120112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21102110191 - 2³¹ = 18954626543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102110171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551055095 + 10551055096.

It is an arithmetic number, because the mean of its divisors is an integer number (10551055096).

Almost surely, 2^21102110191 is an apocalyptic number.

21102110191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102110191 is an equidigital number, since it uses as much as digits as its factorization.

21102110191 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21102110191 in words is "twenty-one billion, one hundred two million, one hundred ten thousand, one hundred ninety-one".