161138609 has 2 divisors, whose sum is σ = 161138610. Its totient is φ = 161138608.

The previous prime is 161138561. The next prime is 161138623. The reversal of 161138609 is 906831161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116208400 + 44930209 = 10780^2 + 6703^2 .

It is an emirp because it is prime and its reverse (906831161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161138609 - 2¹² = 161134513 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161138009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80569304 + 80569305.

It is an arithmetic number, because the mean of its divisors is an integer number (80569305).

Almost surely, 2^161138609 is an apocalyptic number.

It is an amenable number.

161138609 is a deficient number, since it is larger than the sum of its proper divisors (1).

161138609 is an equidigital number, since it uses as much as digits as its factorization.

161138609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 161138609 is about 12694.0383251351. The cubic root of 161138609 is about 544.1682557415.

The spelling of 161138609 in words is "one hundred sixty-one million, one hundred thirty-eight thousand, six hundred nine".