161317847811 has 4 divisors (see below), whose sum is σ = 215090463752. Its totient is φ = 107545231872.

The previous prime is 161317847809. The next prime is 161317847903. The reversal of 161317847811 is 118748713161.

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

It is not a de Polignac number, because 161317847811 - 2¹ = 161317847809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161317847011) 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, 26886307966 + ... + 26886307971.

It is an arithmetic number, because the mean of its divisors is an integer number (53772615938).

Almost surely, 2^161317847811 is an apocalyptic number.

161317847811 is a deficient number, since it is larger than the sum of its proper divisors (53772615941).

161317847811 is an equidigital number, since it uses as much as digits as its factorization.

161317847811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53772615940.

The product of its digits is 225792, while the sum is 48.

The spelling of 161317847811 in words is "one hundred sixty-one billion, three hundred seventeen million, eight hundred forty-seven thousand, eight hundred eleven".