171871643 has 2 divisors, whose sum is σ = 171871644. Its totient is φ = 171871642.

The previous prime is 171871597. The next prime is 171871691. The reversal of 171871643 is 346178171.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 171871643 - 2¹² = 171867547 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 171871597 and 171871606.

It is not a weakly prime, because it can be changed into another prime (171871943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85935821 + 85935822.

It is an arithmetic number, because the mean of its divisors is an integer number (85935822).

Almost surely, 2^171871643 is an apocalyptic number.

171871643 is a deficient number, since it is larger than the sum of its proper divisors (1).

171871643 is an equidigital number, since it uses as much as digits as its factorization.

171871643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 38.

The square root of 171871643 is about 13109.9825705452. The cubic root of 171871643 is about 555.9914027879.

The spelling of 171871643 in words is "one hundred seventy-one million, eight hundred seventy-one thousand, six hundred forty-three".