1320718666 has 8 divisors (see below), whose sum is σ = 1983403044. Its totient is φ = 659584320.

The previous prime is 1320718643. The next prime is 1320718687. The reversal of 1320718666 is 6668170231.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1240096225 + 80622441 = 35215^2 + 8979^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385375 + ... + 388786.

Almost surely, 2^1320718666 is an apocalyptic number.

1320718666 is a deficient number, since it is larger than the sum of its proper divisors (662684378).

1320718666 is an equidigital number, since it uses as much as digits as its factorization.

1320718666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775016.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 1320718666 is about 36341.6932186710. The cubic root of 1320718666 is about 1097.1603523476.

Adding to 1320718666 its reverse (6668170231), we get a palindrome (7988888897).

The spelling of 1320718666 in words is "one billion, three hundred twenty million, seven hundred eighteen thousand, six hundred sixty-six".