1686905899 has 16 divisors (see below), whose sum is σ = 2070784000. Its totient is φ = 1369813032.

The previous prime is 1686905897. The next prime is 1686905929. The reversal of 1686905899 is 9985096861.

It is a happy number.

It is not a de Polignac number, because 1686905899 - 2¹ = 1686905897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1686905893) 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, 122907 + ... + 135940.

It is an arithmetic number, because the mean of its divisors is an integer number (129424000).

Almost surely, 2^1686905899 is an apocalyptic number.

1686905899 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1686905899 is a deficient number, since it is larger than the sum of its proper divisors (383878101).

1686905899 is an equidigital number, since it uses as much as digits as its factorization.

1686905899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258887 (or 258873 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 61.

The square root of 1686905899 is about 41071.9600092326. The cubic root of 1686905899 is about 1190.4110575321.

The spelling of 1686905899 in words is "one billion, six hundred eighty-six million, nine hundred five thousand, eight hundred ninety-nine".