688118866 has 4 divisors (see below), whose sum is σ = 1032178302. Its totient is φ = 344059432.

The previous prime is 688118863. The next prime is 688118881. The reversal of 688118866 is 668811886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 668811886 = 2 ⋅334405943.

It can be written as a sum of positive squares in only one way, i.e., 437688241 + 250430625 = 20921^2 + 15825^2 .

It is not an unprimeable number, because it can be changed into a prime (688118863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172029715 + ... + 172029718.

Almost surely, 2^688118866 is an apocalyptic number.

688118866 is a deficient number, since it is larger than the sum of its proper divisors (344059436).

688118866 is a wasteful number, since it uses less digits than its factorization.

688118866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344059435.

The product of its digits is 884736, while the sum is 52.

The square root of 688118866 is about 26232.0198612307. The cubic root of 688118866 is about 882.8518301726.

It can be divided in two parts, 68811 and 8866, that added together give a palindrome (77677).

The spelling of 688118866 in words is "six hundred eighty-eight million, one hundred eighteen thousand, eight hundred sixty-six".