161585873 has 4 divisors (see below), whose sum is σ = 165343728. Its totient is φ = 157828020.

The previous prime is 161585869. The next prime is 161585891. The reversal of 161585873 is 378585161.

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: 378585161 = 83 ⋅4561267.

It is a cyclic number.

It is not a de Polignac number, because 161585873 - 2² = 161585869 is a prime.

It is a super-2 number, since 2×161585873² = 52219988706344258, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161585863) 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 3 ways as a sum of consecutive naturals, for example, 1878863 + ... + 1878948.

It is an arithmetic number, because the mean of its divisors is an integer number (41335932).

Almost surely, 2^161585873 is an apocalyptic number.

It is an amenable number.

161585873 is a deficient number, since it is larger than the sum of its proper divisors (3757855).

161585873 is an equidigital number, since it uses as much as digits as its factorization.

161585873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3757854.

The product of its digits is 201600, while the sum is 44.

The square root of 161585873 is about 12711.6432061319. The cubic root of 161585873 is about 544.6712637490.

The spelling of 161585873 in words is "one hundred sixty-one million, five hundred eighty-five thousand, eight hundred seventy-three".