161006605 has 4 divisors (see below), whose sum is σ = 193207932. Its totient is φ = 128805280.

The previous prime is 161006603. The next prime is 161006611. The reversal of 161006605 is 506600161.

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 100260169 + 60746436 = 10013^2 + 7794^2 .

It is not a de Polignac number, because 161006605 - 2¹ = 161006603 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 161006605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161006603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16100656 + ... + 16100665.

It is an arithmetic number, because the mean of its divisors is an integer number (48301983).

Almost surely, 2^161006605 is an apocalyptic number.

It is an amenable number.

161006605 is a deficient number, since it is larger than the sum of its proper divisors (32201327).

161006605 is an equidigital number, since it uses as much as digits as its factorization.

161006605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32201326.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 161006605 is about 12688.8378112418. The cubic root of 161006605 is about 544.0196217782.

Adding to 161006605 its reverse (506600161), we get a palindrome (667606766).

The spelling of 161006605 in words is "one hundred sixty-one million, six thousand, six hundred five".