1688688387 has 24 divisors (see below), whose sum is σ = 2608295040. Its totient is φ = 1049068800.

The previous prime is 1688688349. The next prime is 1688688409. The reversal of 1688688387 is 7838868861.

It is not a de Polignac number, because 1688688387 - 2⁷ = 1688688259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1688688317) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39187 + ... + 70092.

It is an arithmetic number, because the mean of its divisors is an integer number (108678960).

Almost surely, 2^1688688387 is an apocalyptic number.

1688688387 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1688688387 is a deficient number, since it is larger than the sum of its proper divisors (919606653).

1688688387 is a wasteful number, since it uses less digits than its factorization.

1688688387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109403 (or 109400 counting only the distinct ones).

The product of its digits is 24772608, while the sum is 63.

The square root of 1688688387 is about 41093.6538531195. The cubic root of 1688688387 is about 1190.8301969934.

The spelling of 1688688387 in words is "one billion, six hundred eighty-eight million, six hundred eighty-eight thousand, three hundred eighty-seven".