666959578 has 8 divisors (see below), whose sum is σ = 1000591668. Its totient is φ = 333429024.

The previous prime is 666959551. The next prime is 666959581. The reversal of 666959578 is 875959666.

It can be written as a sum of positive squares in 2 ways, for example, as 500730129 + 166229449 = 22377^2 + 12893^2 .

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, 6001 + ... + 37012.

Almost surely, 2^666959578 is an apocalyptic number.

666959578 is a deficient number, since it is larger than the sum of its proper divisors (333632090).

666959578 is a wasteful number, since it uses less digits than its factorization.

666959578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50768.

The product of its digits is 24494400, while the sum is 61.

The square root of 666959578 is about 25825.5605553878. The cubic root of 666959578 is about 873.7083868126.

The spelling of 666959578 in words is "six hundred sixty-six million, nine hundred fifty-nine thousand, five hundred seventy-eight".