165660065 has 4 divisors (see below), whose sum is σ = 198792084. Its totient is φ = 132528048.

The previous prime is 165660041. The next prime is 165660067. The reversal of 165660065 is 560066561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 560066561 = 463 ⋅1209647.

It can be written as a sum of positive squares in 2 ways, for example, as 50140561 + 115519504 = 7081^2 + 10748^2 .

It is a cyclic number.

It is not a de Polignac number, because 165660065 - 2²² = 161465761 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165660067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16566002 + ... + 16566011.

It is an arithmetic number, because the mean of its divisors is an integer number (49698021).

Almost surely, 2^165660065 is an apocalyptic number.

It is an amenable number.

165660065 is a deficient number, since it is larger than the sum of its proper divisors (33132019).

165660065 is an equidigital number, since it uses as much as digits as its factorization.

165660065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33132018.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 165660065 is about 12870.8999296863. The cubic root of 165660065 is about 549.2110616992.

The spelling of 165660065 in words is "one hundred sixty-five million, six hundred sixty thousand, sixty-five".