666680071 has 2 divisors, whose sum is σ = 666680072. Its totient is φ = 666680070.

The previous prime is 666680033. The next prime is 666680081. The reversal of 666680071 is 170086666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666680071 - 2¹³ = 666671879 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666680081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333340035 + 333340036.

It is an arithmetic number, because the mean of its divisors is an integer number (333340036).

Almost surely, 2^666680071 is an apocalyptic number.

666680071 is a deficient number, since it is larger than the sum of its proper divisors (1).

666680071 is an equidigital number, since it uses as much as digits as its factorization.

666680071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 666680071 is about 25820.1485472102. The cubic root of 666680071 is about 873.5863195789.

The spelling of 666680071 in words is "six hundred sixty-six million, six hundred eighty thousand, seventy-one".