161847703809 has 81 divisors (see below), whose sum is σ = 262102517859. Its totient is φ = 96166509120.

The previous prime is 161847703757. The next prime is 161847703817. The reversal of 161847703809 is 908307748161.

The square root of 161847703809 is 402303.

It is a perfect power (a square), and thus also a powerful number.

161847703809 is a `hidden beast` number, since 16 + 184 + 7 + 70 + 380 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 91872641025 + 69975062784 = 303105^2 + 264528^2 .

It is not a de Polignac number, because 161847703809 - 2²⁹ = 161310832897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161847703889) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 969147844 + ... + 969148010.

Almost surely, 2^161847703809 is an apocalyptic number.

161847703809 is the 402303-rd square number.

161847703809 is the 201152-nd centered octagonal number.

It is an amenable number.

161847703809 is a deficient number, since it is larger than the sum of its proper divisors (100254814050).

161847703809 is an equidigital number, since it uses as much as digits as its factorization.

161847703809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508 (or 254 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 54.

The spelling of 161847703809 in words is "one hundred sixty-one billion, eight hundred forty-seven million, seven hundred three thousand, eight hundred nine".