161204659009 has 9 divisors (see below), whose sum is σ = 161826563619. Its totient is φ = 160585139880.

The previous prime is 161204659001. The next prime is 161204659043. The reversal of 161204659009 is 900956402161.

The square root of 161204659009 is 401503.

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

It can be written as a sum of positive squares in only one way, i.e., 6576399025 + 154628259984 = 81095^2 + 393228^2 .

It is not a de Polignac number, because 161204659009 - 2³ = 161204659001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161204659001) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 132896887 + ... + 132898099.

It is an arithmetic number, because the mean of its divisors is an integer number (17980729291).

Almost surely, 2^161204659009 is an apocalyptic number.

161204659009 is the 401503-rd square number.

161204659009 is the 200752-nd centered octagonal number.

It is an amenable number.

161204659009 is a deficient number, since it is larger than the sum of its proper divisors (621904610).

161204659009 is an frugal number, since it uses more digits than its factorization.

161204659009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3088 (or 1544 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 43.

The spelling of 161204659009 in words is "one hundred sixty-one billion, two hundred four million, six hundred fifty-nine thousand, nine".