161252909 has 2 divisors, whose sum is σ = 161252910. Its totient is φ = 161252908.

The previous prime is 161252899. The next prime is 161252947. The reversal of 161252909 is 909252161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125372809 + 35880100 = 11197^2 + 5990^2 .

It is an emirp because it is prime and its reverse (909252161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161252909 - 2¹⁶ = 161187373 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161252969) 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, 80626454 + 80626455.

It is an arithmetic number, because the mean of its divisors is an integer number (80626455).

Almost surely, 2^161252909 is an apocalyptic number.

It is an amenable number.

161252909 is a deficient number, since it is larger than the sum of its proper divisors (1).

161252909 is an equidigital number, since it uses as much as digits as its factorization.

161252909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 161252909 is about 12698.5396404468. The cubic root of 161252909 is about 544.2968897820.

The spelling of 161252909 in words is "one hundred sixty-one million, two hundred fifty-two thousand, nine hundred nine".