21711020171 has 2 divisors, whose sum is σ = 21711020172. Its totient is φ = 21711020170.

The previous prime is 21711020167. The next prime is 21711020237. The reversal of 21711020171 is 17102011712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21711020171 - 2² = 21711020167 is a prime.

It is not a weakly prime, because it can be changed into another prime (21711020101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855510085 + 10855510086.

It is an arithmetic number, because the mean of its divisors is an integer number (10855510086).

Almost surely, 2^21711020171 is an apocalyptic number.

21711020171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21711020171 is an equidigital number, since it uses as much as digits as its factorization.

21711020171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 196, while the sum is 23.

Adding to 21711020171 its reverse (17102011712), we get a palindrome (38813031883).

The spelling of 21711020171 in words is "twenty-one billion, seven hundred eleven million, twenty thousand, one hundred seventy-one".