161604 has 27 divisors (see below), whose sum is σ = 414687. Its totient is φ = 53064.

The previous prime is 161599. The next prime is 161611. The reversal of 161604 is 406161.

161604 = T₄₀₁ + T₄₀₂.

The square root of 161604 is 402.

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

161604 is a `hidden beast` number, since 1 + 61 + 604 = 666.

161604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161604² = 52231705632, which contains 22 as substring.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2379 + ... + 2445.

2¹⁶¹⁶⁰⁴ is an apocalyptic number.

161604 is the 402-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161604

161604 is an abundant number, since it is smaller than the sum of its proper divisors (253083).

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

161604 is a wasteful number, since it uses less digits than its factorization.

161604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The cubic root of 161604 is about 54.4691630395.

Multiplying 161604 by its product of nonzero digits (144), we get a square (23270976 = 4824²).

Adding to 161604 its reverse (406161), we get a palindrome (567765).

The spelling of 161604 in words is "one hundred sixty-one thousand, six hundred four".