66646507 has 2 divisors, whose sum is σ = 66646508. Its totient is φ = 66646506.

The previous prime is 66646487. The next prime is 66646513. The reversal of 66646507 is 70564666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66646507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66646507.

It is not a weakly prime, because it can be changed into another prime (66646207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33323253 + 33323254.

It is an arithmetic number, because the mean of its divisors is an integer number (33323254).

Almost surely, 2^66646507 is an apocalyptic number.

66646507 is a deficient number, since it is larger than the sum of its proper divisors (1).

66646507 is an equidigital number, since it uses as much as digits as its factorization.

66646507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 66646507 is about 8163.7311935168. The cubic root of 66646507 is about 405.4392571961.

The spelling of 66646507 in words is "sixty-six million, six hundred forty-six thousand, five hundred seven".