688704655 has 8 divisors (see below), whose sum is σ = 827788752. Its totient is φ = 550068288.

The previous prime is 688704637. The next prime is 688704689. The reversal of 688704655 is 556407886.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 688704655 - 2⁵ = 688704623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 688704599 and 688704608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108537 + ... + 114706.

It is an arithmetic number, because the mean of its divisors is an integer number (103473594).

Almost surely, 2^688704655 is an apocalyptic number.

688704655 is a deficient number, since it is larger than the sum of its proper divisors (139084097).

688704655 is a wasteful number, since it uses less digits than its factorization.

688704655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223865.

The product of its (nonzero) digits is 1612800, while the sum is 49.

The square root of 688704655 is about 26243.1830195958. The cubic root of 688704655 is about 883.1022802199.

The spelling of 688704655 in words is "six hundred eighty-eight million, seven hundred four thousand, six hundred fifty-five".