1688889866 has 8 divisors (see below), whose sum is σ = 2533675140. Its totient is φ = 844331488.

The previous prime is 1688889863. The next prime is 1688889883. The reversal of 1688889866 is 6689888861.

It can be written as a sum of positive squares in 2 ways, for example, as 1608411025 + 80478841 = 40105^2 + 8971^2 .

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1688889796 and 1688889805.

It is not an unprimeable number, because it can be changed into a prime (1688889863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36701 + ... + 68736.

Almost surely, 2^1688889866 is an apocalyptic number.

1688889866 is a deficient number, since it is larger than the sum of its proper divisors (844785274).

1688889866 is a wasteful number, since it uses less digits than its factorization.

1688889866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113448.

The product of its digits is 63700992, while the sum is 68.

The square root of 1688889866 is about 41096.1052412513. The cubic root of 1688889866 is about 1190.8775548004.

The spelling of 1688889866 in words is "one billion, six hundred eighty-eight million, eight hundred eighty-nine thousand, eight hundred sixty-six".