161041865 has 4 divisors (see below), whose sum is σ = 193250244. Its totient is φ = 128833488.

The previous prime is 161041861. The next prime is 161041873. The reversal of 161041865 is 568140161.

161041865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 568140161 = 881 ⋅644881.

It can be written as a sum of positive squares in 2 ways, for example, as 97377424 + 63664441 = 9868^2 + 7979^2 .

It is a cyclic number.

It is not a de Polignac number, because 161041865 - 2² = 161041861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161041861) 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, 16104182 + ... + 16104191.

It is an arithmetic number, because the mean of its divisors is an integer number (48312561).

Almost surely, 2^161041865 is an apocalyptic number.

It is an amenable number.

161041865 is a deficient number, since it is larger than the sum of its proper divisors (32208379).

161041865 is an equidigital number, since it uses as much as digits as its factorization.

161041865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32208378.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 161041865 is about 12690.2271453272. The cubic root of 161041865 is about 544.0593318090.

The spelling of 161041865 in words is "one hundred sixty-one million, forty-one thousand, eight hundred sixty-five".