165728641 has 4 divisors (see below), whose sum is σ = 178477012. Its totient is φ = 152980272.

The previous prime is 165728623. The next prime is 165728653. The reversal of 165728641 is 146827561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 146827561 = 23 ⋅6383807.

It can be written as a sum of positive squares in 2 ways, for example, as 33593616 + 132135025 = 5796^2 + 11495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165728641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165728594 and 165728603.

It is not an unprimeable number, because it can be changed into a prime (165728611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6374166 + ... + 6374191.

It is an arithmetic number, because the mean of its divisors is an integer number (44619253).

Almost surely, 2^165728641 is an apocalyptic number.

It is an amenable number.

165728641 is a deficient number, since it is larger than the sum of its proper divisors (12748371).

165728641 is a wasteful number, since it uses less digits than its factorization.

165728641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12748370.

The product of its digits is 80640, while the sum is 40.

The square root of 165728641 is about 12873.5636480347. The cubic root of 165728641 is about 549.2868343405.

The spelling of 165728641 in words is "one hundred sixty-five million, seven hundred twenty-eight thousand, six hundred forty-one".