171742409 has 2 divisors, whose sum is σ = 171742410. Its totient is φ = 171742408.

The previous prime is 171742367. The next prime is 171742411. The reversal of 171742409 is 904247171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108889225 + 62853184 = 10435^2 + 7928^2 .

It is a cyclic number.

It is not a de Polignac number, because 171742409 - 2¹² = 171738313 is a prime.

It is a Sophie Germain prime.

Together with 171742411, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (171742429) 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, 85871204 + 85871205.

It is an arithmetic number, because the mean of its divisors is an integer number (85871205).

Almost surely, 2^171742409 is an apocalyptic number.

It is an amenable number.

171742409 is a deficient number, since it is larger than the sum of its proper divisors (1).

171742409 is an equidigital number, since it uses as much as digits as its factorization.

171742409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 171742409 is about 13105.0528041668. The cubic root of 171742409 is about 555.8520138647.

The spelling of 171742409 in words is "one hundred seventy-one million, seven hundred forty-two thousand, four hundred nine".