161186609 has 2 divisors, whose sum is σ = 161186610. Its totient is φ = 161186608.

The previous prime is 161186593. The next prime is 161186647. The reversal of 161186609 is 906681161.

It is an a-pointer prime, because the next prime (161186647) can be obtained adding 161186609 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96432400 + 64754209 = 9820^2 + 8047^2 .

It is a cyclic number.

It is not a de Polignac number, because 161186609 - 2⁴ = 161186593 is a prime.

It is a super-2 number, since 2×161186609² = 51962245841837762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161186659) 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, 80593304 + 80593305.

It is an arithmetic number, because the mean of its divisors is an integer number (80593305).

Almost surely, 2^161186609 is an apocalyptic number.

It is an amenable number.

161186609 is a deficient number, since it is larger than the sum of its proper divisors (1).

161186609 is an equidigital number, since it uses as much as digits as its factorization.

161186609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 161186609 is about 12695.9288356544. The cubic root of 161186609 is about 544.2222826924. Note that the first 4 decimals are identical.

Adding to 161186609 its product of nonzero digits (15552), we get a palindrome (161202161).

The spelling of 161186609 in words is "one hundred sixty-one million, one hundred eighty-six thousand, six hundred nine".