668856655 has 8 divisors (see below), whose sum is σ = 804042000. Its totient is φ = 534142656.

The previous prime is 668856647. The next prime is 668856697. The reversal of 668856655 is 556658866.

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

It is a cyclic number.

It is not a de Polignac number, because 668856655 - 2³ = 668856647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 668856596 and 668856605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114705 + ... + 120394.

It is an arithmetic number, because the mean of its divisors is an integer number (100505250).

Almost surely, 2^668856655 is an apocalyptic number.

668856655 is a deficient number, since it is larger than the sum of its proper divisors (135185345).

668856655 is a wasteful number, since it uses less digits than its factorization.

668856655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235673.

The product of its digits is 10368000, while the sum is 55.

The square root of 668856655 is about 25862.2631453630. The cubic root of 668856655 is about 874.5359847230.

The spelling of 668856655 in words is "six hundred sixty-eight million, eight hundred fifty-six thousand, six hundred fifty-five".