165561729 has 8 divisors (see below), whose sum is σ = 224490720. Its totient is φ = 108503616.

The previous prime is 165561719. The next prime is 165561743. The reversal of 165561729 is 927165561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165561729 - 2¹³ = 165553537 is a prime.

It is a super-2 number, since 2×165561729² = 54821372218938882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165561719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 467512 + ... + 467865.

It is an arithmetic number, because the mean of its divisors is an integer number (28061340).

Almost surely, 2^165561729 is an apocalyptic number.

It is an amenable number.

165561729 is a deficient number, since it is larger than the sum of its proper divisors (58928991).

165561729 is an equidigital number, since it uses as much as digits as its factorization.

165561729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935439.

The product of its digits is 113400, while the sum is 42.

The square root of 165561729 is about 12867.0792723135. The cubic root of 165561729 is about 549.1023694228.

The spelling of 165561729 in words is "one hundred sixty-five million, five hundred sixty-one thousand, seven hundred twenty-nine".