161328985 has 4 divisors (see below), whose sum is σ = 193594788. Its totient is φ = 129063184.

The previous prime is 161328971. The next prime is 161329027. The reversal of 161328985 is 589823161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 589823161 = 163 ⋅3618547.

It can be written as a sum of positive squares in 2 ways, for example, as 69705801 + 91623184 = 8349^2 + 9572^2 .

It is a cyclic number.

It is not a de Polignac number, because 161328985 - 2¹³ = 161320793 is a prime.

It is a super-2 number, since 2×161328985² = 52054082802260450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16132894 + ... + 16132903.

It is an arithmetic number, because the mean of its divisors is an integer number (48398697).

Almost surely, 2^161328985 is an apocalyptic number.

It is an amenable number.

161328985 is a deficient number, since it is larger than the sum of its proper divisors (32265803).

161328985 is an equidigital number, since it uses as much as digits as its factorization.

161328985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32265802.

The product of its digits is 103680, while the sum is 43.

The square root of 161328985 is about 12701.5347497852. The cubic root of 161328985 is about 544.3824725690.

The spelling of 161328985 in words is "one hundred sixty-one million, three hundred twenty-eight thousand, nine hundred eighty-five".