21331210171 has 2 divisors, whose sum is σ = 21331210172. Its totient is φ = 21331210170.

The previous prime is 21331210133. The next prime is 21331210223. The reversal of 21331210171 is 17101213312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21331210171 - 2¹⁵ = 21331177403 is a prime.

It is not a weakly prime, because it can be changed into another prime (21331211171) 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, 10665605085 + 10665605086.

It is an arithmetic number, because the mean of its divisors is an integer number (10665605086).

Almost surely, 2^21331210171 is an apocalyptic number.

21331210171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331210171 is an equidigital number, since it uses as much as digits as its factorization.

21331210171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 22.

Adding to 21331210171 its reverse (17101213312), we get a palindrome (38432423483).

The spelling of 21331210171 in words is "twenty-one billion, three hundred thirty-one million, two hundred ten thousand, one hundred seventy-one".