668908946 has 16 divisors (see below), whose sum is σ = 1080736800. Its totient is φ = 309482208.

The previous prime is 668908943. The next prime is 668908949. The reversal of 668908946 is 649809866.

It is an interprime number because it is at equal distance from previous prime (668908943) and next prime (668908949).

It is a junction number, because it is equal to n+sod(n) for n = 668908891 and 668908900.

It is not an unprimeable number, because it can be changed into a prime (668908943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 203051 + ... + 206318.

It is an arithmetic number, because the mean of its divisors is an integer number (67546050).

Almost surely, 2^668908946 is an apocalyptic number.

668908946 is a deficient number, since it is larger than the sum of its proper divisors (411827854).

668908946 is a wasteful number, since it uses less digits than its factorization.

668908946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409433.

The product of its (nonzero) digits is 4478976, while the sum is 56.

The square root of 668908946 is about 25863.2740773476. The cubic root of 668908946 is about 874.5587744439.

The spelling of 668908946 in words is "six hundred sixty-eight million, nine hundred eight thousand, nine hundred forty-six".