1681111 has 4 divisors (see below), whose sum is σ = 1685992. Its totient is φ = 1676232.

The previous prime is 1681103. The next prime is 1681129. The reversal of 1681111 is 1111861.

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 1681111 - 2³ = 1681103 is a prime.

It is a super-2 number, since 2×1681111² = 5652268388642, which contains 22 as substring.

It is a Duffinian number.

1681111 is a modest number, since divided by 1111 gives 168 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681151) 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 in 3 ways as a sum of consecutive naturals, for example, 1881 + ... + 2626.

It is an arithmetic number, because the mean of its divisors is an integer number (421498).

2^1681111 is an apocalyptic number.

1681111 is a deficient number, since it is larger than the sum of its proper divisors (4881).

1681111 is an equidigital number, since it uses as much as digits as its factorization.

1681111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4880.

The product of its digits is 48, while the sum is 19.

The square root of 1681111 is about 1296.5766464039. The cubic root of 1681111 is about 118.9046384288.

Adding to 1681111 its reverse (1111861), we get a palindrome (2792972).

The spelling of 1681111 in words is "one million, six hundred eighty-one thousand, one hundred eleven".