165535720 has 48 divisors (see below), whose sum is σ = 433269540. Its totient is φ = 56754432.

The previous prime is 165535693. The next prime is 165535759. The reversal of 165535720 is 27535561.

It can be written as a sum of positive squares in 2 ways, for example, as 165533956 + 1764 = 12866^2 + 42^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40269 + ... + 44188.

Almost surely, 2^165535720 is an apocalyptic number.

165535720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165535720 is an abundant number, since it is smaller than the sum of its proper divisors (267733820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165535720 is a wasteful number, since it uses less digits than its factorization.

165535720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84482 (or 84471 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 34.

The square root of 165535720 is about 12866.0685525921. The cubic root of 165535720 is about 549.0736140827.

The spelling of 165535720 in words is "one hundred sixty-five million, five hundred thirty-five thousand, seven hundred twenty".