199664173 has 18 divisors (see below), whose sum is σ = 216507242. Its totient is φ = 183981600.

The previous prime is 199664123. The next prime is 199664183. The reversal of 199664173 is 371466991.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 174292804 + 25371369 = 13202^2 + 5037^2 .

It is not a de Polignac number, because 199664173 - 2²¹ = 197567021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199664123) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1976823 + ... + 1976923.

Almost surely, 2^199664173 is an apocalyptic number.

It is an amenable number.

199664173 is a deficient number, since it is larger than the sum of its proper divisors (16843069).

199664173 is an equidigital number, since it uses as much as digits as its factorization.

199664173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285 (or 161 counting only the distinct ones).

The product of its digits is 244944, while the sum is 46.

The square root of 199664173 is about 14130.2573578828. The cubic root of 199664173 is about 584.4760428976.

The spelling of 199664173 in words is "one hundred ninety-nine million, six hundred sixty-four thousand, one hundred seventy-three".