161081709 has 4 divisors (see below), whose sum is σ = 214775616. Its totient is φ = 107387804.

The previous prime is 161081707. The next prime is 161081729. The reversal of 161081709 is 907180161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161081709 - 2¹ = 161081707 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161081709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161081707) 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, 26846949 + ... + 26846954.

It is an arithmetic number, because the mean of its divisors is an integer number (53693904).

Almost surely, 2^161081709 is an apocalyptic number.

It is an amenable number.

161081709 is a deficient number, since it is larger than the sum of its proper divisors (53693907).

161081709 is an equidigital number, since it uses as much as digits as its factorization.

161081709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53693906.

The product of its (nonzero) digits is 3024, while the sum is 33.

The square root of 161081709 is about 12691.7969176945. The cubic root of 161081709 is about 544.1041973941.

The spelling of 161081709 in words is "one hundred sixty-one million, eighty-one thousand, seven hundred nine".