16609181 has 4 divisors (see below), whose sum is σ = 16622652. Its totient is φ = 16595712.

The previous prime is 16609171. The next prime is 16609207. The reversal of 16609181 is 18190661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8797156 + 7812025 = 2966^2 + 2795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16609181 is a prime.

It is a super-2 number, since 2×16609181² = 551729786981522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16609111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4676 + ... + 7421.

It is an arithmetic number, because the mean of its divisors is an integer number (4155663).

Almost surely, 2^16609181 is an apocalyptic number.

It is an amenable number.

16609181 is a deficient number, since it is larger than the sum of its proper divisors (13471).

16609181 is a wasteful number, since it uses less digits than its factorization.

16609181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13470.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 16609181 is about 4075.4362956621. The cubic root of 16609181 is about 255.1424604457.

The spelling of 16609181 in words is "sixteen million, six hundred nine thousand, one hundred eighty-one".