66642271 has 2 divisors, whose sum is σ = 66642272. Its totient is φ = 66642270.

The previous prime is 66642263. The next prime is 66642311. The reversal of 66642271 is 17224666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66642271 - 2³ = 66642263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66642071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33321135 + 33321136.

It is an arithmetic number, because the mean of its divisors is an integer number (33321136).

Almost surely, 2^66642271 is an apocalyptic number.

66642271 is a deficient number, since it is larger than the sum of its proper divisors (1).

66642271 is an equidigital number, since it uses as much as digits as its factorization.

66642271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 34.

The square root of 66642271 is about 8163.4717492008. The cubic root of 66642271 is about 405.4306672131.

The spelling of 66642271 in words is "sixty-six million, six hundred forty-two thousand, two hundred seventy-one".