161449865 has 4 divisors (see below), whose sum is σ = 193739844. Its totient is φ = 129159888.

The previous prime is 161449861. The next prime is 161449877. The reversal of 161449865 is 568944161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 568944161 = 179 ⋅3178459.

It can be written as a sum of positive squares in 2 ways, for example, as 96098809 + 65351056 = 9803^2 + 8084^2 .

It is a cyclic number.

It is not a de Polignac number, because 161449865 - 2² = 161449861 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161449861) 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, 16144982 + ... + 16144991.

It is an arithmetic number, because the mean of its divisors is an integer number (48434961).

Almost surely, 2^161449865 is an apocalyptic number.

It is an amenable number.

161449865 is a deficient number, since it is larger than the sum of its proper divisors (32289979).

161449865 is an equidigital number, since it uses as much as digits as its factorization.

161449865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32289978.

The product of its digits is 207360, while the sum is 44.

The square root of 161449865 is about 12706.2923388375. The cubic root of 161449865 is about 544.5184029367.

The spelling of 161449865 in words is "one hundred sixty-one million, four hundred forty-nine thousand, eight hundred sixty-five".