1688117693789 has 2 divisors, whose sum is σ = 1688117693790. Its totient is φ = 1688117693788.

The previous prime is 1688117693783. The next prime is 1688117693791. The reversal of 1688117693789 is 9873967118861.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1431033202564 + 257084491225 = 1196258^2 + 507035^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688117693789 - 2³² = 1683822726493 is a prime.

It is a Sophie Germain prime.

Together with 1688117693791, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1688117693783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844058846894 + 844058846895.

It is an arithmetic number, because the mean of its divisors is an integer number (844058846895).

Almost surely, 2^{1688117693789} is an apocalyptic number.

It is an amenable number.

1688117693789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688117693789 is an equidigital number, since it uses as much as digits as its factorization.

1688117693789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 219469824, while the sum is 74.

The spelling of 1688117693789 in words is "one trillion, six hundred eighty-eight billion, one hundred seventeen million, six hundred ninety-three thousand, seven hundred eighty-nine".