21127111171 has 2 divisors, whose sum is σ = 21127111172. Its totient is φ = 21127111170.

The previous prime is 21127111163. The next prime is 21127111189. The reversal of 21127111171 is 17111172112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21127111171 - 2³ = 21127111163 is a prime.

It is not a weakly prime, because it can be changed into another prime (21127115171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563555585 + 10563555586.

It is an arithmetic number, because the mean of its divisors is an integer number (10563555586).

Almost surely, 2^21127111171 is an apocalyptic number.

21127111171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127111171 is an equidigital number, since it uses as much as digits as its factorization.

21127111171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 196, while the sum is 25.

Adding to 21127111171 its reverse (17111172112), we get a palindrome (38238283283).

The spelling of 21127111171 in words is "twenty-one billion, one hundred twenty-seven million, one hundred eleven thousand, one hundred seventy-one".