165638395 has 16 divisors (see below), whose sum is σ = 226648800. Its totient is φ = 115121664.

The previous prime is 165638357. The next prime is 165638411. The reversal of 165638395 is 593836561.

It is a cyclic number.

It is not a de Polignac number, because 165638395 - 2¹⁷ = 165507323 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73845 + ... + 76054.

It is an arithmetic number, because the mean of its divisors is an integer number (14165550).

Almost surely, 2^165638395 is an apocalyptic number.

165638395 is a deficient number, since it is larger than the sum of its proper divisors (61010405).

165638395 is a wasteful number, since it uses less digits than its factorization.

165638395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149934.

The product of its digits is 583200, while the sum is 46.

The square root of 165638395 is about 12870.0580806770. The cubic root of 165638395 is about 549.1871132143.

The spelling of 165638395 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, three hundred ninety-five".