165765647 has 4 divisors (see below), whose sum is σ = 165968376. Its totient is φ = 165562920.

The previous prime is 165765643. The next prime is 165765707. The reversal of 165765647 is 746567561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 746567561 = 29 ⋅25743709.

It is a cyclic number.

It is not a de Polignac number, because 165765647 - 2² = 165765643 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165765641) 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 3 ways as a sum of consecutive naturals, for example, 100133 + ... + 101774.

It is an arithmetic number, because the mean of its divisors is an integer number (41492094).

Almost surely, 2^165765647 is an apocalyptic number.

165765647 is a deficient number, since it is larger than the sum of its proper divisors (202729).

165765647 is an equidigital number, since it uses as much as digits as its factorization.

165765647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202728.

The product of its digits is 1058400, while the sum is 47.

The square root of 165765647 is about 12875.0008543689. Note that the first 3 decimals coincide. The cubic root of 165765647 is about 549.3277152161.

The spelling of 165765647 in words is "one hundred sixty-five million, seven hundred sixty-five thousand, six hundred forty-seven".