165538505 has 16 divisors (see below), whose sum is σ = 217496448. Its totient is φ = 119952000.

The previous prime is 165538459. The next prime is 165538511. The reversal of 165538505 is 505835561.

It is not a de Polignac number, because 165538505 - 2¹² = 165534409 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10100 + ... + 20810.

It is an arithmetic number, because the mean of its divisors is an integer number (13593528).

Almost surely, 2^165538505 is an apocalyptic number.

It is an amenable number.

165538505 is a deficient number, since it is larger than the sum of its proper divisors (51957943).

165538505 is a wasteful number, since it uses less digits than its factorization.

165538505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11008.

The product of its (nonzero) digits is 90000, while the sum is 38.

The square root of 165538505 is about 12866.1767825567. The cubic root of 165538505 is about 549.0766933002.

The spelling of 165538505 in words is "one hundred sixty-five million, five hundred thirty-eight thousand, five hundred five".