668839456 has 12 divisors (see below), whose sum is σ = 1316777742. Its totient is φ = 334419712.

The previous prime is 668839439. The next prime is 668839459. The reversal of 668839456 is 654938866.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 668739600 + 99856 = 25860^2 + 316^2 .

It is a junction number, because it is equal to n+sod(n) for n = 668839397 and 668839406.

It is not an unprimeable number, because it can be changed into a prime (668839459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10450585 + ... + 10450648.

Almost surely, 2^668839456 is an apocalyptic number.

It is an amenable number.

668839456 is a deficient number, since it is larger than the sum of its proper divisors (647938286).

668839456 is a wasteful number, since it uses less digits than its factorization.

668839456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20901243 (or 20901235 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 55.

The square root of 668839456 is about 25861.9306317220. The cubic root of 668839456 is about 874.5284887106.

The spelling of 668839456 in words is "six hundred sixty-eight million, eight hundred thirty-nine thousand, four hundred fifty-six".