161517204 has 108 divisors (see below), whose sum is σ = 445919292. Its totient is φ = 49121280.

The previous prime is 161517199. The next prime is 161517217. The reversal of 161517204 is 402715161.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 40297104 + 121220100 = 6348^2 + 11010^2 .

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 1028694 + ... + 1028850.

Almost surely, 2^161517204 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161517204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (222959646).

161517204 is an abundant number, since it is smaller than the sum of its proper divisors (284402088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161517204 is a wasteful number, since it uses less digits than its factorization.

161517204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 161517204 is about 12708.9418914401. The cubic root of 161517204 is about 544.5940966679.

The spelling of 161517204 in words is "one hundred sixty-one million, five hundred seventeen thousand, two hundred four".