66571 has 2 divisors, whose sum is σ = 66572. Its totient is φ = 66570.

The previous prime is 66569. The next prime is 66587. The reversal of 66571 is 17566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66571 - 2¹ = 66569 is a prime.

Together with 66569, it forms a pair of twin primes.

It is a plaindrome in base 9.

It is not a weakly prime, because it can be changed into another prime (66541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33285 + 33286.

It is an arithmetic number, because the mean of its divisors is an integer number (33286).

2⁶⁶⁵⁷¹ is an apocalyptic number.

66571 is a deficient number, since it is larger than the sum of its proper divisors (1).

66571 is an equidigital number, since it uses as much as digits as its factorization.

66571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 25.

The square root of 66571 is about 258.0135655348. The cubic root of 66571 is about 40.5286085526.

The spelling of 66571 in words is "sixty-six thousand, five hundred seventy-one".