688636609256 has 8 divisors (see below), whose sum is σ = 1291193642370. Its totient is φ = 344318304624.

The previous prime is 688636609231. The next prime is 688636609261. The reversal of 688636609256 is 652906636886.

It can be written as a sum of positive squares in only one way, i.e., 671727768100 + 16908841156 = 819590^2 + 130034^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 688636609192 and 688636609201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43039788071 + ... + 43039788086.

Almost surely, 2^688636609256 is an apocalyptic number.

It is an amenable number.

688636609256 is a deficient number, since it is larger than the sum of its proper divisors (602557033114).

688636609256 is a wasteful number, since it uses less digits than its factorization.

688636609256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86079576163 (or 86079576159 counting only the distinct ones).

The product of its (nonzero) digits is 134369280, while the sum is 65.

The spelling of 688636609256 in words is "six hundred eighty-eight billion, six hundred thirty-six million, six hundred nine thousand, two hundred fifty-six".