161737109 has 4 divisors (see below), whose sum is σ = 161947116. Its totient is φ = 161527104.

The previous prime is 161737073. The next prime is 161737111. The reversal of 161737109 is 901737161.

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 35736484 + 126000625 = 5978^2 + 11225^2 .

It is a cyclic number.

It is not a de Polignac number, because 161737109 - 2⁸ = 161736853 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161737189) 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, 103844 + ... + 105389.

It is an arithmetic number, because the mean of its divisors is an integer number (40486779).

Almost surely, 2^161737109 is an apocalyptic number.

It is an amenable number.

161737109 is a deficient number, since it is larger than the sum of its proper divisors (210007).

161737109 is an equidigital number, since it uses as much as digits as its factorization.

161737109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210006.

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 161737109 is about 12717.5905343740. The cubic root of 161737109 is about 544.8411387837.

The spelling of 161737109 in words is "one hundred sixty-one million, seven hundred thirty-seven thousand, one hundred nine".