165859873 has 4 divisors (see below), whose sum is σ = 174589360. Its totient is φ = 157130388.

The previous prime is 165859861. The next prime is 165859909. The reversal of 165859873 is 378958561.

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, and also an emirpimes, since its reverse is a distinct semiprime: 378958561 = 353 ⋅1073537.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165859873 is a prime.

It is a super-2 number, since 2×165859873² = 55018994943152258, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165859873.

It is not an unprimeable number, because it can be changed into a prime (165859823) 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, 4364715 + ... + 4364752.

It is an arithmetic number, because the mean of its divisors is an integer number (43647340).

Almost surely, 2^165859873 is an apocalyptic number.

It is an amenable number.

165859873 is a deficient number, since it is larger than the sum of its proper divisors (8729487).

165859873 is an equidigital number, since it uses as much as digits as its factorization.

165859873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8729486.

The product of its digits is 1814400, while the sum is 52.

The square root of 165859873 is about 12878.6595964021. The cubic root of 165859873 is about 549.4317801009.

The spelling of 165859873 in words is "one hundred sixty-five million, eight hundred fifty-nine thousand, eight hundred seventy-three".