668478925 has 6 divisors (see below), whose sum is σ = 828913898. Its totient is φ = 534783120.

The previous prime is 668478893. The next prime is 668478953. The reversal of 668478925 is 529874866.

It can be written as a sum of positive squares in 3 ways, for example, as 137499076 + 530979849 = 11726^2 + 23043^2 .

It is not a de Polignac number, because 668478925 - 2⁵ = 668478893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13369554 + ... + 13369603.

Almost surely, 2^668478925 is an apocalyptic number.

It is an amenable number.

668478925 is a deficient number, since it is larger than the sum of its proper divisors (160434973).

668478925 is a wasteful number, since it uses less digits than its factorization.

668478925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26739167 (or 26739162 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 55.

The square root of 668478925 is about 25854.9593888677. The cubic root of 668478925 is about 874.3713252853.

The spelling of 668478925 in words is "six hundred sixty-eight million, four hundred seventy-eight thousand, nine hundred twenty-five".