161323919 has 2 divisors, whose sum is σ = 161323920. Its totient is φ = 161323918.

The previous prime is 161323913. The next prime is 161323949. The reversal of 161323919 is 919323161.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161323919 is a prime.

It is a super-2 number, since 2×161323919² = 52050813683037122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161323913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80661959 + 80661960.

It is an arithmetic number, because the mean of its divisors is an integer number (80661960).

Almost surely, 2^161323919 is an apocalyptic number.

161323919 is a deficient number, since it is larger than the sum of its proper divisors (1).

161323919 is an equidigital number, since it uses as much as digits as its factorization.

161323919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 35.

The square root of 161323919 is about 12701.3353235004. The cubic root of 161323919 is about 544.3767743359.

The spelling of 161323919 in words is "one hundred sixty-one million, three hundred twenty-three thousand, nine hundred nineteen".