161685316 has 12 divisors (see below), whose sum is σ = 304714732. Its totient is φ = 74623968.

The previous prime is 161685313. The next prime is 161685341. The reversal of 161685316 is 613586161.

It can be written as a sum of positive squares in 2 ways, for example, as 100000000 + 61685316 = 10000^2 + 7854^2 .

It is a super-2 number, since 2×161685316² = 52284282820039712, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161685313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1554615 + ... + 1554718.

Almost surely, 2^161685316 is an apocalyptic number.

It is an amenable number.

161685316 is a deficient number, since it is larger than the sum of its proper divisors (143029416).

161685316 is a wasteful number, since it uses less digits than its factorization.

161685316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3109350 (or 3109348 counting only the distinct ones).

The product of its digits is 25920, while the sum is 37.

The square root of 161685316 is about 12715.5540972464. The cubic root of 161685316 is about 544.7829744989.

The spelling of 161685316 in words is "one hundred sixty-one million, six hundred eighty-five thousand, three hundred sixteen".