165861065 has 12 divisors (see below), whose sum is σ = 200667972. Its totient is φ = 131607840.

The previous prime is 165861043. The next prime is 165861079. The reversal of 165861065 is 560168561.

It can be written as a sum of positive squares in 2 ways, for example, as 86508601 + 79352464 = 9301^2 + 8908^2 .

It is not a de Polignac number, because 165861065 - 2⁶ = 165861001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84839 + ... + 86771.

It is an arithmetic number, because the mean of its divisors is an integer number (16722331).

Almost surely, 2^165861065 is an apocalyptic number.

It is an amenable number.

165861065 is a deficient number, since it is larger than the sum of its proper divisors (34806907).

165861065 is an equidigital number, since it uses as much as digits as its factorization.

165861065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200 (or 2069 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 165861065 is about 12878.7058744270. The cubic root of 165861065 is about 549.4330963146.

The spelling of 165861065 in words is "one hundred sixty-five million, eight hundred sixty-one thousand, sixty-five".