1688312117 has 6 divisors (see below), whose sum is σ = 1692315234. Its totient is φ = 1684313040.

The previous prime is 1688312113. The next prime is 1688312137. The reversal of 1688312117 is 7112138861.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 540051121 + 1148260996 = 23239^2 + 33886^2 .

It is not a de Polignac number, because 1688312117 - 2² = 1688312113 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688312113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 968867 + ... + 970607.

It is an arithmetic number, because the mean of its divisors is an integer number (282052539).

Almost surely, 2^1688312117 is an apocalyptic number.

It is an amenable number.

1688312117 is a deficient number, since it is larger than the sum of its proper divisors (4003117).

1688312117 is an frugal number, since it uses more digits than its factorization.

1688312117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4039 (or 2298 counting only the distinct ones).

The product of its digits is 16128, while the sum is 38.

The square root of 1688312117 is about 41089.0753972391. The cubic root of 1688312117 is about 1190.7417443290.

The spelling of 1688312117 in words is "one billion, six hundred eighty-eight million, three hundred twelve thousand, one hundred seventeen".