161838805 has 4 divisors (see below), whose sum is σ = 194206572. Its totient is φ = 129471040.

The previous prime is 161838791. The next prime is 161838823. The reversal of 161838805 is 508838161.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19704721 + 142134084 = 4439^2 + 11922^2 .

It is not a de Polignac number, because 161838805 - 2⁵ = 161838773 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16183876 + ... + 16183885.

It is an arithmetic number, because the mean of its divisors is an integer number (48551643).

Almost surely, 2^161838805 is an apocalyptic number.

It is an amenable number.

161838805 is a deficient number, since it is larger than the sum of its proper divisors (32367767).

161838805 is an equidigital number, since it uses as much as digits as its factorization.

161838805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32367766.

The product of its (nonzero) digits is 46080, while the sum is 40.

The square root of 161838805 is about 12721.5881477117. The cubic root of 161838805 is about 544.9553087389.

The spelling of 161838805 in words is "one hundred sixty-one million, eight hundred thirty-eight thousand, eight hundred five".