165551565 has 8 divisors (see below), whose sum is σ = 264882528. Its totient is φ = 88294160.

The previous prime is 165551527. The next prime is 165551569. The reversal of 165551565 is 565155561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165551565 - 2¹³ = 165543373 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165551569) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5518371 + ... + 5518400.

It is an arithmetic number, because the mean of its divisors is an integer number (33110316).

Almost surely, 2^165551565 is an apocalyptic number.

165551565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165551565 is a deficient number, since it is larger than the sum of its proper divisors (99330963).

165551565 is a wasteful number, since it uses less digits than its factorization.

165551565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11036779.

The product of its digits is 112500, while the sum is 39.

The square root of 165551565 is about 12866.6843048238. The cubic root of 165551565 is about 549.0911325451.

The spelling of 165551565 in words is "one hundred sixty-five million, five hundred fifty-one thousand, five hundred sixty-five".