663705686 has 16 divisors (see below), whose sum is σ = 1161002400. Its totient is φ = 284445000.

The previous prime is 663705671. The next prime is 663705689. The reversal of 663705686 is 686507366.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 663705686.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663705689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 483065 + ... + 484436.

It is an arithmetic number, because the mean of its divisors is an integer number (72562650).

Almost surely, 2^663705686 is an apocalyptic number.

663705686 is a deficient number, since it is larger than the sum of its proper divisors (497296714).

663705686 is an equidigital number, since it uses as much as digits as its factorization.

663705686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 967524 (or 967510 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 47.

The square root of 663705686 is about 25762.4860213451. The cubic root of 663705686 is about 872.2852178054.

The spelling of 663705686 in words is "six hundred sixty-three million, seven hundred five thousand, six hundred eighty-six".