663686707 has 4 divisors (see below), whose sum is σ = 670528936. Its totient is φ = 656844480.

The previous prime is 663686687. The next prime is 663686711. The reversal of 663686707 is 707686366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663686707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663686717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3420969 + ... + 3421162.

It is an arithmetic number, because the mean of its divisors is an integer number (167632234).

Almost surely, 2^663686707 is an apocalyptic number.

663686707 is a deficient number, since it is larger than the sum of its proper divisors (6842229).

663686707 is an equidigital number, since it uses as much as digits as its factorization.

663686707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6842228.

The product of its (nonzero) digits is 1524096, while the sum is 49.

The square root of 663686707 is about 25762.1176730485. The cubic root of 663686707 is about 872.2769032471.

The spelling of 663686707 in words is "six hundred sixty-three million, six hundred eighty-six thousand, seven hundred seven".