1681439 has 4 divisors (see below), whose sum is σ = 1687224. Its totient is φ = 1675656.

The previous prime is 1681423. The next prime is 1681469. The reversal of 1681439 is 9341861.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1681439 - 2⁴ = 1681423 is a prime.

It is a super-2 number, since 2×1681439² = 5654474221442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2432 + ... + 3045.

It is an arithmetic number, because the mean of its divisors is an integer number (421806).

2^1681439 is an apocalyptic number.

1681439 is a deficient number, since it is larger than the sum of its proper divisors (5785).

1681439 is an equidigital number, since it uses as much as digits as its factorization.

1681439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5784.

The product of its digits is 5184, while the sum is 32.

The square root of 1681439 is about 1296.7031271652. The cubic root of 1681439 is about 118.9123710503.

The spelling of 1681439 in words is "one million, six hundred eighty-one thousand, four hundred thirty-nine".