165729 has 4 divisors (see below), whose sum is σ = 220976. Its totient is φ = 110484.

The previous prime is 165721. The next prime is 165749. The reversal of 165729 is 927561.

165729 is nontrivially palindromic in base 6.

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 not a de Polignac number, because 165729 - 2³ = 165721 is a prime.

It is a super-2 number, since 2×165729² = 54932202882, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 165696 and 165705.

It is not an unprimeable number, because it can be changed into a prime (165721) 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, 27619 + ... + 27624.

It is an arithmetic number, because the mean of its divisors is an integer number (55244).

2¹⁶⁵⁷²⁹ is an apocalyptic number.

It is an amenable number.

165729 is a deficient number, since it is larger than the sum of its proper divisors (55247).

165729 is an equidigital number, since it uses as much as digits as its factorization.

165729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55246.

The product of its digits is 3780, while the sum is 30.

The square root of 165729 is about 407.0982682351. The cubic root of 165729 is about 54.9287230960.

The spelling of 165729 in words is "one hundred sixty-five thousand, seven hundred twenty-nine".