165399671 has 2 divisors, whose sum is σ = 165399672. Its totient is φ = 165399670.

The previous prime is 165399667. The next prime is 165399679. The reversal of 165399671 is 176993561.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165399671 - 2² = 165399667 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165399679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82699835 + 82699836.

It is an arithmetic number, because the mean of its divisors is an integer number (82699836).

Almost surely, 2^165399671 is an apocalyptic number.

165399671 is a deficient number, since it is larger than the sum of its proper divisors (1).

165399671 is an equidigital number, since it uses as much as digits as its factorization.

165399671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 306180, while the sum is 47.

The square root of 165399671 is about 12860.7803417989. The cubic root of 165399671 is about 548.9231503031.

The spelling of 165399671 in words is "one hundred sixty-five million, three hundred ninety-nine thousand, six hundred seventy-one".