1687393 has 2 divisors, whose sum is σ = 1687394. Its totient is φ = 1687392.

The previous prime is 1687381. The next prime is 1687421. The reversal of 1687393 is 3937861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1682209 + 5184 = 1297^2 + 72^2 .

It is an emirp because it is prime and its reverse (3937861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1687393 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1687373) 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 as a sum of consecutive naturals, namely, 843696 + 843697.

It is an arithmetic number, because the mean of its divisors is an integer number (843697).

2^1687393 is an apocalyptic number.

It is an amenable number.

1687393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687393 is an equidigital number, since it uses as much as digits as its factorization.

1687393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 37.

The square root of 1687393 is about 1298.9969207046. The cubic root of 1687393 is about 119.0525625198.

It can be divided in two parts, 1687 and 393, that added together give a triangular number (2080 = T₆₄).

The spelling of 1687393 in words is "one million, six hundred eighty-seven thousand, three hundred ninety-three".