165321623 has 4 divisors (see below), whose sum is σ = 165486480. Its totient is φ = 165156768.

The previous prime is 165321619. The next prime is 165321647. The reversal of 165321623 is 326123561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165321623 - 2² = 165321619 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 (165321323) 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, 80915 + ... + 82932.

It is an arithmetic number, because the mean of its divisors is an integer number (41371620).

Almost surely, 2^165321623 is an apocalyptic number.

165321623 is a deficient number, since it is larger than the sum of its proper divisors (164857).

165321623 is a wasteful number, since it uses less digits than its factorization.

165321623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164856.

The product of its digits is 6480, while the sum is 29.

The square root of 165321623 is about 12857.7456422189. The cubic root of 165321623 is about 548.8367956481.

The spelling of 165321623 in words is "one hundred sixty-five million, three hundred twenty-one thousand, six hundred twenty-three".