21431134171 has 2 divisors, whose sum is σ = 21431134172. Its totient is φ = 21431134170.

The previous prime is 21431134169. The next prime is 21431134223. The reversal of 21431134171 is 17143113412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21431134171 - 2¹ = 21431134169 is a prime.

Together with 21431134169, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21431132171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715567085 + 10715567086.

It is an arithmetic number, because the mean of its divisors is an integer number (10715567086).

Almost surely, 2^21431134171 is an apocalyptic number.

21431134171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21431134171 is an equidigital number, since it uses as much as digits as its factorization.

21431134171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 28.

Adding to 21431134171 its reverse (17143113412), we get a palindrome (38574247583).

The spelling of 21431134171 in words is "twenty-one billion, four hundred thirty-one million, one hundred thirty-four thousand, one hundred seventy-one".