668729744 has 20 divisors (see below), whose sum is σ = 1298007324. Its totient is φ = 333760128.

The previous prime is 668729741. The next prime is 668729783. The reversal of 668729744 is 447927866.

It can be written as a sum of positive squares in 2 ways, for example, as 44729344 + 624000400 = 6688^2 + 24980^2 .

It is not an unprimeable number, because it can be changed into a prime (668729741) 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, 28607 + ... + 46430.

Almost surely, 2^668729744 is an apocalyptic number.

It is an amenable number.

668729744 is a deficient number, since it is larger than the sum of its proper divisors (629277580).

668729744 is a wasteful number, since it uses less digits than its factorization.

668729744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75602 (or 75596 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 53.

The square root of 668729744 is about 25859.8094347194. The cubic root of 668729744 is about 874.4806688064.

The spelling of 668729744 in words is "six hundred sixty-eight million, seven hundred twenty-nine thousand, seven hundred forty-four".