1687489 has 2 divisors, whose sum is σ = 1687490. Its totient is φ = 1687488.

The previous prime is 1687453. The next prime is 1687507. The reversal of 1687489 is 9847861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1669264 + 18225 = 1292^2 + 135^2 .

It is a cyclic number.

It is not a de Polignac number, because 1687489 - 2¹¹ = 1685441 is a prime.

It is not a weakly prime, because it can be changed into another prime (1687289) 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, 843744 + 843745.

It is an arithmetic number, because the mean of its divisors is an integer number (843745).

2^1687489 is an apocalyptic number.

It is an amenable number.

1687489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687489 is an equidigital number, since it uses as much as digits as its factorization.

1687489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 1687489 is about 1299.0338717678. The cubic root of 1687489 is about 119.0548202095.

The spelling of 1687489 in words is "one million, six hundred eighty-seven thousand, four hundred eighty-nine".