66969871 has 2 divisors, whose sum is σ = 66969872. Its totient is φ = 66969870.

The previous prime is 66969869. The next prime is 66969893. The reversal of 66969871 is 17896966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66969871 - 2¹ = 66969869 is a prime.

Together with 66969869, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66969811) 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, 33484935 + 33484936.

It is an arithmetic number, because the mean of its divisors is an integer number (33484936).

Almost surely, 2^66969871 is an apocalyptic number.

66969871 is a deficient number, since it is larger than the sum of its proper divisors (1).

66969871 is an equidigital number, since it uses as much as digits as its factorization.

66969871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 52.

The square root of 66969871 is about 8183.5121433282. The cubic root of 66969871 is about 406.0939201291.

The spelling of 66969871 in words is "sixty-six million, nine hundred sixty-nine thousand, eight hundred seventy-one".