165535663 has 4 divisors (see below), whose sum is σ = 165719080. Its totient is φ = 165352248.

The previous prime is 165535609. The next prime is 165535679. The reversal of 165535663 is 366535561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 366535561 = 7 ⋅52362223.

It is a cyclic number.

It is not a de Polignac number, because 165535663 - 2¹³ = 165527471 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 (165535693) 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, 90348 + ... + 92161.

It is an arithmetic number, because the mean of its divisors is an integer number (41429770).

Almost surely, 2^165535663 is an apocalyptic number.

165535663 is a deficient number, since it is larger than the sum of its proper divisors (183417).

165535663 is an equidigital number, since it uses as much as digits as its factorization.

165535663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183416.

The product of its digits is 243000, while the sum is 40.

The square root of 165535663 is about 12866.0663374631. The cubic root of 165535663 is about 549.0735510607.

The spelling of 165535663 in words is "one hundred sixty-five million, five hundred thirty-five thousand, six hundred sixty-three".