1681619 has 2 divisors, whose sum is σ = 1681620. Its totient is φ = 1681618.

The previous prime is 1681597. The next prime is 1681621. The reversal of 1681619 is 9161861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1681619 - 2⁸ = 1681363 is a prime.

It is a super-2 number, since 2×1681619² = 5655684922322, which contains 22 as substring.

Together with 1681621, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (1681639) 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 as a sum of consecutive naturals, namely, 840809 + 840810.

It is an arithmetic number, because the mean of its divisors is an integer number (840810).

2^1681619 is an apocalyptic number.

1681619 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681619 is an equidigital number, since it uses as much as digits as its factorization.

1681619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 32.

The square root of 1681619 is about 1296.7725320965. The cubic root of 1681619 is about 118.9166141347.

The spelling of 1681619 in words is "one million, six hundred eighty-one thousand, six hundred nineteen".