1688431305 has 16 divisors (see below), whose sum is σ = 2947080384. Its totient is φ = 818633280.

The previous prime is 1688431267. The next prime is 1688431307. The reversal of 1688431305 is 5031348861.

It is not a de Polignac number, because 1688431305 - 2¹¹ = 1688429257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1688431307) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5116294 + ... + 5116623.

It is an arithmetic number, because the mean of its divisors is an integer number (184192524).

Almost surely, 2^1688431305 is an apocalyptic number.

1688431305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1688431305 is a deficient number, since it is larger than the sum of its proper divisors (1258649079).

1688431305 is a wasteful number, since it uses less digits than its factorization.

1688431305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10232936.

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 1688431305 is about 41090.5257328256. The cubic root of 1688431305 is about 1190.7697641850.

The spelling of 1688431305 in words is "one billion, six hundred eighty-eight million, four hundred thirty-one thousand, three hundred five".