1688999999 has 2 divisors, whose sum is σ = 1689000000. Its totient is φ = 1688999998.

The previous prime is 1688999953. The next prime is 1689000067. The reversal of 1688999999 is 9999998861.

It is a weak prime.

It is an emirp because it is prime and its reverse (9999998861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1688999999 - 2²⁰ = 1687951423 is a prime.

1688999999 is a modest number, since divided by 99999 gives 16889 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1688992999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844499999 + 844500000.

It is an arithmetic number, because the mean of its divisors is an integer number (844500000).

Almost surely, 2^1688999999 is an apocalyptic number.

1688999999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688999999 is an equidigital number, since it uses as much as digits as its factorization.

1688999999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204073344, while the sum is 77.

The square root of 1688999999 is about 41097.4451639028. The cubic root of 1688999999 is about 1190.9034400618.

The spelling of 1688999999 in words is "one billion, six hundred eighty-eight million, nine hundred ninety-nine thousand, nine hundred ninety-nine".