668694158 has 24 divisors (see below), whose sum is σ = 1104218136. Its totient is φ = 303482960.

The previous prime is 668694127. The next prime is 668694193. The reversal of 668694158 is 851496866.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 191141 + ... + 194607.

It is an arithmetic number, because the mean of its divisors is an integer number (46009089).

Almost surely, 2^668694158 is an apocalyptic number.

668694158 is a deficient number, since it is larger than the sum of its proper divisors (435523978).

668694158 is a wasteful number, since it uses less digits than its factorization.

668694158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4288 (or 4277 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 53.

The square root of 668694158 is about 25859.1213694511. The cubic root of 668694158 is about 874.4651568993.

The spelling of 668694158 in words is "six hundred sixty-eight million, six hundred ninety-four thousand, one hundred fifty-eight".