1687320817 has 32 divisors (see below), whose sum is σ = 2160139520. Its totient is φ = 1282417920.

The previous prime is 1687320809. The next prime is 1687320841. The reversal of 1687320817 is 7180237861.

It is not a de Polignac number, because 1687320817 - 2³ = 1687320809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is not an unprimeable number, because it can be changed into a prime (1687320617) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 235159 + ... + 242227.

It is an arithmetic number, because the mean of its divisors is an integer number (67504360).

Almost surely, 2^1687320817 is an apocalyptic number.

It is an amenable number.

1687320817 is a deficient number, since it is larger than the sum of its proper divisors (472818703).

1687320817 is a wasteful number, since it uses less digits than its factorization.

1687320817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7193.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 1687320817 is about 41077.0108089671. The cubic root of 1687320817 is about 1190.5086489242.

The spelling of 1687320817 in words is "one billion, six hundred eighty-seven million, three hundred twenty thousand, eight hundred seventeen".