161243605867 has 4 divisors (see below), whose sum is σ = 161259931000. Its totient is φ = 161227280736.

The previous prime is 161243605837. The next prime is 161243605877. The reversal of 161243605867 is 768506342161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 768506342161 = 19 ⋅40447702219.

It is a cyclic number.

It is not a de Polignac number, because 161243605867 - 2¹¹ = 161243603819 is a prime.

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 161243605867.

It is not an unprimeable number, because it can be changed into a prime (161243605807) 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, 8147742 + ... + 8167507.

It is an arithmetic number, because the mean of its divisors is an integer number (40314982750).

Almost surely, 2^161243605867 is an apocalyptic number.

161243605867 is a deficient number, since it is larger than the sum of its proper divisors (16325133).

161243605867 is an equidigital number, since it uses as much as digits as its factorization.

161243605867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16325132.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 161243605867 in words is "one hundred sixty-one billion, two hundred forty-three million, six hundred five thousand, eight hundred sixty-seven".