643250171 has 2 divisors, whose sum is σ = 643250172. Its totient is φ = 643250170.

The previous prime is 643250129. The next prime is 643250173. The reversal of 643250171 is 171052346.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643250171 is a prime.

Together with 643250173, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643250173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321625085 + 321625086.

It is an arithmetic number, because the mean of its divisors is an integer number (321625086).

Almost surely, 2^643250171 is an apocalyptic number.

643250171 is a deficient number, since it is larger than the sum of its proper divisors (1).

643250171 is an equidigital number, since it uses as much as digits as its factorization.

643250171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 643250171 is about 25362.3770770801. The cubic root of 643250171 is about 863.2302220622.

The spelling of 643250171 in words is "six hundred forty-three million, two hundred fifty thousand, one hundred seventy-one".