66640267 has 2 divisors, whose sum is σ = 66640268. Its totient is φ = 66640266.

The previous prime is 66640253. The next prime is 66640271. The reversal of 66640267 is 76204666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66640267 - 2⁷ = 66640139 is a prime.

It is a super-3 number, since 3×66640267³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (66640237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33320133 + 33320134.

It is an arithmetic number, because the mean of its divisors is an integer number (33320134).

Almost surely, 2^66640267 is an apocalyptic number.

66640267 is a deficient number, since it is larger than the sum of its proper divisors (1).

66640267 is an equidigital number, since it uses as much as digits as its factorization.

66640267 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 37.

The square root of 66640267 is about 8163.3490063821. The cubic root of 66640267 is about 405.4266032700.

The spelling of 66640267 in words is "sixty-six million, six hundred forty thousand, two hundred sixty-seven".