1689739 has 2 divisors, whose sum is σ = 1689740. Its totient is φ = 1689738.

The previous prime is 1689719. The next prime is 1689757. The reversal of 1689739 is 9379861.

It is a strong prime.

It is an emirp because it is prime and its reverse (9379861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1689739 - 2⁵ = 1689707 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1689695 and 1689704.

It is not a weakly prime, because it can be changed into another prime (1689719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844869 + 844870.

It is an arithmetic number, because the mean of its divisors is an integer number (844870).

2^1689739 is an apocalyptic number.

1689739 is a deficient number, since it is larger than the sum of its proper divisors (1).

1689739 is an equidigital number, since it uses as much as digits as its factorization.

1689739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 43.

The square root of 1689739 is about 1299.8996115085. The cubic root of 1689739 is about 119.1077103079.

The spelling of 1689739 in words is "one million, six hundred eighty-nine thousand, seven hundred thirty-nine".