161173504 has 78 divisors (see below), whose sum is σ = 343284810. Its totient is φ = 75644928.

The previous prime is 161173487. The next prime is 161173511. The reversal of 161173504 is 405371161.

It can be written as a sum of positive squares in only one way, i.e., 147865600 + 13307904 = 12160^2 + 3648^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1478602 + ... + 1478710.

Almost surely, 2^161173504 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 161173504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171642405).

161173504 is an abundant number, since it is smaller than the sum of its proper divisors (182111306).

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

161173504 is an equidigital number, since it uses as much as digits as its factorization.

161173504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 161173504 is about 12695.4127148352. The cubic root of 161173504 is about 544.2075332738.

The spelling of 161173504 in words is "one hundred sixty-one million, one hundred seventy-three thousand, five hundred four".