165660549 has 4 divisors (see below), whose sum is σ = 220880736. Its totient is φ = 110440364.

The previous prime is 165660533. The next prime is 165660569. The reversal of 165660549 is 945066561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165660549 - 2⁴ = 165660533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165660549.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165660569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27610089 + ... + 27610094.

It is an arithmetic number, because the mean of its divisors is an integer number (55220184).

Almost surely, 2^165660549 is an apocalyptic number.

It is an amenable number.

165660549 is a deficient number, since it is larger than the sum of its proper divisors (55220187).

165660549 is an equidigital number, since it uses as much as digits as its factorization.

165660549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55220186.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 165660549 is about 12870.9187317767. The cubic root of 165660549 is about 549.2115965654.

The spelling of 165660549 in words is "one hundred sixty-five million, six hundred sixty thousand, five hundred forty-nine".