1688968817 has 2 divisors, whose sum is σ = 1688968818. Its totient is φ = 1688968816.

The previous prime is 1688968781. The next prime is 1688968871. The reversal of 1688968817 is 7188698861.

Together with next prime (1688968871) it forms an Ormiston pair, because they use the same digits, order apart.

Together with previous prime (1688968781) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1578949696 + 110019121 = 39736^2 + 10489^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688968817 - 2³⁰ = 615226993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1688968817.

It is not a weakly prime, because it can be changed into another prime (1688968217) by changing a digit.

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, 844484408 + 844484409.

It is an arithmetic number, because the mean of its divisors is an integer number (844484409).

Almost surely, 2^1688968817 is an apocalyptic number.

It is an amenable number.

1688968817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688968817 is an equidigital number, since it uses as much as digits as its factorization.

1688968817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9289728, while the sum is 62.

The square root of 1688968817 is about 41097.0657955042. The cubic root of 1688968817 is about 1190.8961112717.

The spelling of 1688968817 in words is "one billion, six hundred eighty-eight million, nine hundred sixty-eight thousand, eight hundred seventeen".