66906871 has 2 divisors, whose sum is σ = 66906872. Its totient is φ = 66906870.

The previous prime is 66906869. The next prime is 66906887. The reversal of 66906871 is 17860966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66906871 - 2¹ = 66906869 is a prime.

Together with 66906869, 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 (66906821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33453435 + 33453436.

It is an arithmetic number, because the mean of its divisors is an integer number (33453436).

Almost surely, 2^66906871 is an apocalyptic number.

66906871 is a deficient number, since it is larger than the sum of its proper divisors (1).

66906871 is an equidigital number, since it uses as much as digits as its factorization.

66906871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 66906871 is about 8179.6620345831. The cubic root of 66906871 is about 405.9665397453.

The spelling of 66906871 in words is "sixty-six million, nine hundred six thousand, eight hundred seventy-one".