66717187 has 2 divisors, whose sum is σ = 66717188. Its totient is φ = 66717186.

The previous prime is 66717149. The next prime is 66717199. The reversal of 66717187 is 78171766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66717187 - 2¹⁹ = 66192899 is a prime.

It is not a weakly prime, because it can be changed into another prime (66717107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33358593 + 33358594.

It is an arithmetic number, because the mean of its divisors is an integer number (33358594).

Almost surely, 2^66717187 is an apocalyptic number.

66717187 is a deficient number, since it is larger than the sum of its proper divisors (1).

66717187 is an equidigital number, since it uses as much as digits as its factorization.

66717187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784, while the sum is 43.

The square root of 66717187 is about 8168.0589493465. The cubic root of 66717187 is about 405.5825321338.

The spelling of 66717187 in words is "sixty-six million, seven hundred seventeen thousand, one hundred eighty-seven".