1681879 has 2 divisors, whose sum is σ = 1681880. Its totient is φ = 1681878.

The previous prime is 1681877. The next prime is 1681891. The reversal of 1681879 is 9781861.

It is a weak prime.

It is an emirp because it is prime and its reverse (9781861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1681879 - 2¹ = 1681877 is a prime.

Together with 1681877, it forms a pair of twin primes.

It is an Ulam number.

1681879 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681871) 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, 840939 + 840940.

It is an arithmetic number, because the mean of its divisors is an integer number (840940).

2^1681879 is an apocalyptic number.

1681879 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681879 is an equidigital number, since it uses as much as digits as its factorization.

1681879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The square root of 1681879 is about 1296.8727771065. The cubic root of 1681879 is about 118.9227425000.

Adding to 1681879 its product of digits (24192), we get a palindrome (1706071).

The spelling of 1681879 in words is "one million, six hundred eighty-one thousand, eight hundred seventy-nine".