1687668 has 12 divisors (see below), whose sum is σ = 3937920. Its totient is φ = 562552.

The previous prime is 1687667. The next prime is 1687669. The reversal of 1687668 is 8667861.

It is an interprime number because it is at equal distance from previous prime (1687667) and next prime (1687669).

It is a tau number, because it is divible by the number of its divisors (12).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1687661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70308 + ... + 70331.

It is an arithmetic number, because the mean of its divisors is an integer number (328160).

2^1687668 is an apocalyptic number.

It is an amenable number.

1687668 is an abundant number, since it is smaller than the sum of its proper divisors (2250252).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1687668 is a wasteful number, since it uses less digits than its factorization.

1687668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140646 (or 140644 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 1687668 is about 1299.1027672975. The cubic root of 1687668 is about 119.0590296314.

The spelling of 1687668 in words is "one million, six hundred eighty-seven thousand, six hundred sixty-eight".