63666717 has 16 divisors (see below), whose sum is σ = 91798272. Its totient is φ = 39096320.

The previous prime is 63666697. The next prime is 63666719. The reversal of 63666717 is 71766636.

It is a cyclic number.

It is not a de Polignac number, because 63666717 - 2²³ = 55278109 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63666719) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10884 + ... + 15677.

It is an arithmetic number, because the mean of its divisors is an integer number (5737392).

Almost surely, 2^63666717 is an apocalyptic number.

It is an amenable number.

63666717 is a deficient number, since it is larger than the sum of its proper divisors (28131555).

63666717 is a wasteful number, since it uses less digits than its factorization.

63666717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26628.

The product of its digits is 190512, while the sum is 42.

The square root of 63666717 is about 7979.1426231143. The cubic root of 63666717 is about 399.3044516489.

The spelling of 63666717 in words is "sixty-three million, six hundred sixty-six thousand, seven hundred seventeen".