688689196129 has 27 divisors (see below), whose sum is σ = 778382809491. Its totient is φ = 608861222640.

The previous prime is 688689196127. The next prime is 688689196133. The reversal of 688689196129 is 921691986886.

The square root of 688689196129 is 829873.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 616248550225 + 72440645904 = 785015^2 + 269148^2 .

It is not a de Polignac number, because 688689196129 - 2¹ = 688689196127 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688689196127) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 337757292 + ... + 337759330.

Almost surely, 2^688689196129 is an apocalyptic number.

688689196129 is the 829873-rd square number.

688689196129 is the 414937-th centered octagonal number.

It is an amenable number.

688689196129 is a deficient number, since it is larger than the sum of its proper divisors (89693613362).

688689196129 is an frugal number, since it uses more digits than its factorization.

688689196129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4174 (or 2087 counting only the distinct ones).

The product of its digits is 161243136, while the sum is 73.

The spelling of 688689196129 in words is "six hundred eighty-eight billion, six hundred eighty-nine million, one hundred ninety-six thousand, one hundred twenty-nine".