1687897665 has 96 divisors (see below), whose sum is σ = 3143162880. Its totient is φ = 836035200.

The previous prime is 1687897657. The next prime is 1687897669. The reversal of 1687897665 is 5667987861.

It is not a de Polignac number, because 1687897665 - 2³ = 1687897657 is a prime.

Its product of digits (30481920) is a multiple of the sum of its prime divisors (432).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1687897669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7999410 + ... + 7999620.

It is an arithmetic number, because the mean of its divisors is an integer number (32741280).

Almost surely, 2^1687897665 is an apocalyptic number.

1687897665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1687897665 is a deficient number, since it is larger than the sum of its proper divisors (1455265215).

1687897665 is a wasteful number, since it uses less digits than its factorization.

1687897665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435 (or 432 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 63.

The square root of 1687897665 is about 41084.0317520080. The cubic root of 1687897665 is about 1190.6443007184.

The spelling of 1687897665 in words is "one billion, six hundred eighty-seven million, eight hundred ninety-seven thousand, six hundred sixty-five".