165645353 has 4 divisors (see below), whose sum is σ = 167285508. Its totient is φ = 164005200.

The previous prime is 165645329. The next prime is 165645421. The reversal of 165645353 is 353546561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 353546561 = 101 ⋅3500461.

It can be written as a sum of positive squares in 2 ways, for example, as 88416409 + 77228944 = 9403^2 + 8788^2 .

It is a cyclic number.

It is not a de Polignac number, because 165645353 - 2¹⁸ = 165383209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165645313) 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, 819926 + ... + 820127.

It is an arithmetic number, because the mean of its divisors is an integer number (41821377).

Almost surely, 2^165645353 is an apocalyptic number.

It is an amenable number.

165645353 is a deficient number, since it is larger than the sum of its proper divisors (1640155).

165645353 is a wasteful number, since it uses less digits than its factorization.

165645353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640154.

The product of its digits is 162000, while the sum is 38.

The square root of 165645353 is about 12870.3283951887. The cubic root of 165645353 is about 549.1948030386.

The spelling of 165645353 in words is "one hundred sixty-five million, six hundred forty-five thousand, three hundred fifty-three".