161604540 has 72 divisors (see below), whose sum is σ = 498541680. Its totient is φ = 42361344.

The previous prime is 161604539. The next prime is 161604571. The reversal of 161604540 is 45406161.

161604540 is a `hidden beast` number, since 1 + 6 + 1 + 604 + 54 + 0 = 666.

It is a super-2 number, since 2×161604540² = 52232054697223200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3012 + ... + 18228.

It is an arithmetic number, because the mean of its divisors is an integer number (6924190).

Almost surely, 2^161604540 is an apocalyptic number.

161604540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161604540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249270840).

161604540 is an abundant number, since it is smaller than the sum of its proper divisors (336937140).

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

161604540 is a wasteful number, since it uses less digits than its factorization.

161604540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15291 (or 15286 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 161604540 is about 12712.3774330375. The cubic root of 161604540 is about 544.6922370903.

The spelling of 161604540 in words is "one hundred sixty-one million, six hundred four thousand, five hundred forty".