999986171 has 2 divisors, whose sum is σ = 999986172. Its totient is φ = 999986170.

The previous prime is 999986167. The next prime is 999986173. The reversal of 999986171 is 171689999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999986171 - 2² = 999986167 is a prime.

Together with 999986173, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999986171.

It is not a weakly prime, because it can be changed into another prime (999986173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499993085 + 499993086.

It is an arithmetic number, because the mean of its divisors is an integer number (499993086).

Almost surely, 2^999986171 is an apocalyptic number.

999986171 is a deficient number, since it is larger than the sum of its proper divisors (1).

999986171 is an equidigital number, since it uses as much as digits as its factorization.

999986171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 59.

The square root of 999986171 is about 31622.5579452390. The cubic root of 999986171 is about 999.9953903121.

The spelling of 999986171 in words is "nine hundred ninety-nine million, nine hundred eighty-six thousand, one hundred seventy-one".