688676866 has 4 divisors (see below), whose sum is σ = 1033015302. Its totient is φ = 344338432.

The previous prime is 688676839. The next prime is 688676867. The reversal of 688676866 is 668676886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 668676886 = 2 ⋅334338443.

It can be written as a sum of positive squares in only one way, i.e., 522808225 + 165868641 = 22865^2 + 12879^2 .

It is not an unprimeable number, because it can be changed into a prime (688676867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172169215 + ... + 172169218.

Almost surely, 2^688676866 is an apocalyptic number.

688676866 is a deficient number, since it is larger than the sum of its proper divisors (344338436).

688676866 is a wasteful number, since it uses less digits than its factorization.

688676866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344338435.

The product of its digits is 27869184, while the sum is 61.

The square root of 688676866 is about 26242.6535624734. The cubic root of 688676866 is about 883.0904024340.

The spelling of 688676866 in words is "six hundred eighty-eight million, six hundred seventy-six thousand, eight hundred sixty-six".