161518165567 has 4 divisors (see below), whose sum is σ = 176201635176. Its totient is φ = 146834695960.

The previous prime is 161518165553. The next prime is 161518165579. The reversal of 161518165567 is 765561815161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161518165567 - 2²⁷ = 161383947839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161518135567) 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, 7341734788 + ... + 7341734809.

It is an arithmetic number, because the mean of its divisors is an integer number (44050408794).

Almost surely, 2^161518165567 is an apocalyptic number.

161518165567 is a deficient number, since it is larger than the sum of its proper divisors (14683469609).

161518165567 is a wasteful number, since it uses less digits than its factorization.

161518165567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14683469608.

The product of its digits is 1512000, while the sum is 52.

The spelling of 161518165567 in words is "one hundred sixty-one billion, five hundred eighteen million, one hundred sixty-five thousand, five hundred sixty-seven".