1687859 has 2 divisors, whose sum is σ = 1687860. Its totient is φ = 1687858.

The previous prime is 1687853. The next prime is 1687909. The reversal of 1687859 is 9587861.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1687859 - 2⁴ = 1687843 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1687853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843929 + 843930.

It is an arithmetic number, because the mean of its divisors is an integer number (843930).

2^1687859 is an apocalyptic number.

1687859 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687859 is an equidigital number, since it uses as much as digits as its factorization.

1687859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 44.

The square root of 1687859 is about 1299.1762774928. The cubic root of 1687859 is about 119.0635209209.

The spelling of 1687859 in words is "one million, six hundred eighty-seven thousand, eight hundred fifty-nine".