161689474 has 4 divisors (see below), whose sum is σ = 242534214. Its totient is φ = 80844736.

The previous prime is 161689469. The next prime is 161689477. The reversal of 161689474 is 474986161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 129846025 + 31843449 = 11395^2 + 5643^2 .

It is a super-2 number, since 2×161689474² = 52286972004793352, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161689477) 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 as a sum of consecutive naturals, namely, 40422367 + ... + 40422370.

Almost surely, 2^161689474 is an apocalyptic number.

161689474 is a deficient number, since it is larger than the sum of its proper divisors (80844740).

161689474 is an equidigital number, since it uses as much as digits as its factorization.

161689474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80844739.

The product of its digits is 290304, while the sum is 46.

The square root of 161689474 is about 12715.7175967383. The cubic root of 161689474 is about 544.7876444513.

The spelling of 161689474 in words is "one hundred sixty-one million, six hundred eighty-nine thousand, four hundred seventy-four".