688680665121 has 8 divisors (see below), whose sum is σ = 922250673280. Its totient is φ = 457115550192.

The previous prime is 688680665117. The next prime is 688680665201. The reversal of 688680665121 is 121566086886.

It is a happy number.

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

It is not a de Polignac number, because 688680665121 - 2² = 688680665117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688680665021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 501222505 + ... + 501223878.

It is an arithmetic number, because the mean of its divisors is an integer number (115281334160).

Almost surely, 2^688680665121 is an apocalyptic number.

It is an amenable number.

688680665121 is a deficient number, since it is larger than the sum of its proper divisors (233570008159).

688680665121 is a wasteful number, since it uses less digits than its factorization.

688680665121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1002446615.

The product of its (nonzero) digits is 6635520, while the sum is 57.

The spelling of 688680665121 in words is "six hundred eighty-eight billion, six hundred eighty million, six hundred sixty-five thousand, one hundred twenty-one".