66718247 has 2 divisors, whose sum is σ = 66718248. Its totient is φ = 66718246.

The previous prime is 66718237. The next prime is 66718273. The reversal of 66718247 is 74281766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66718247 - 2¹⁰ = 66717223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66718207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33359123 + 33359124.

It is an arithmetic number, because the mean of its divisors is an integer number (33359124).

Almost surely, 2^66718247 is an apocalyptic number.

66718247 is a deficient number, since it is larger than the sum of its proper divisors (1).

66718247 is an equidigital number, since it uses as much as digits as its factorization.

66718247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 41.

The square root of 66718247 is about 8168.1238359858. The cubic root of 66718247 is about 405.5846800821.

The spelling of 66718247 in words is "sixty-six million, seven hundred eighteen thousand, two hundred forty-seven".