165865129 has 8 divisors (see below), whose sum is σ = 169001352. Its totient is φ = 162758400.

The previous prime is 165865111. The next prime is 165865151. The reversal of 165865129 is 921568561.

It can be written as a sum of positive squares in 4 ways, for example, as 24730729 + 141134400 = 4973^2 + 11880^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 165865129 - 2⁹ = 165864617 is a prime.

It is a super-2 number, since 2×165865129² = 55022482036373282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165865199) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4147 + ... + 18679.

It is an arithmetic number, because the mean of its divisors is an integer number (21125169).

Almost surely, 2^165865129 is an apocalyptic number.

It is an amenable number.

165865129 is a deficient number, since it is larger than the sum of its proper divisors (3136223).

165865129 is a wasteful number, since it uses less digits than its factorization.

165865129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14747.

The product of its digits is 129600, while the sum is 43.

The square root of 165865129 is about 12878.8636532887. The cubic root of 165865129 is about 549.4375837609.

The spelling of 165865129 in words is "one hundred sixty-five million, eight hundred sixty-five thousand, one hundred twenty-nine".