21020201171 has 2 divisors, whose sum is σ = 21020201172. Its totient is φ = 21020201170.

The previous prime is 21020201161. The next prime is 21020201173. The reversal of 21020201171 is 17110202012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020201171 is a prime.

Together with 21020201173, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21020201173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510100585 + 10510100586.

It is an arithmetic number, because the mean of its divisors is an integer number (10510100586).

Almost surely, 2^21020201171 is an apocalyptic number.

21020201171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020201171 is an equidigital number, since it uses as much as digits as its factorization.

21020201171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 17.

Adding to 21020201171 its reverse (17110202012), we get a palindrome (38130403183).

The spelling of 21020201171 in words is "twenty-one billion, twenty million, two hundred one thousand, one hundred seventy-one".