165957865 has 8 divisors (see below), whose sum is σ = 206016840. Its totient is φ = 128188032.

The previous prime is 165957863. The next prime is 165957871. The reversal of 165957865 is 568759561.

It can be written as a sum of positive squares in 4 ways, for example, as 1784896 + 164172969 = 1336^2 + 12813^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 165957865 - 2¹ = 165957863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165957863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 572124 + ... + 572413.

It is an arithmetic number, because the mean of its divisors is an integer number (25752105).

Almost surely, 2^165957865 is an apocalyptic number.

It is an amenable number.

165957865 is a deficient number, since it is larger than the sum of its proper divisors (40058975).

165957865 is a wasteful number, since it uses less digits than its factorization.

165957865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1144571.

The product of its digits is 2268000, while the sum is 52.

The square root of 165957865 is about 12882.4634678310. The cubic root of 165957865 is about 549.5399624246.

The spelling of 165957865 in words is "one hundred sixty-five million, nine hundred fifty-seven thousand, eight hundred sixty-five".