2108681 has 4 divisors (see below), whose sum is σ = 2115732. Its totient is φ = 2101632.

The previous prime is 2108669. The next prime is 2108699. The reversal of 2108681 is 1868012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 379456 + 1729225 = 616^2 + 1315^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2108681 is a prime.

It is a super-2 number, since 2×2108681² = 8893071119522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2108681.

It is not an unprimeable number, because it can be changed into a prime (2108611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3056 + ... + 3681.

It is an arithmetic number, because the mean of its divisors is an integer number (528933).

2^2108681 is an apocalyptic number.

It is an amenable number.

2108681 is a deficient number, since it is larger than the sum of its proper divisors (7051).

2108681 is an equidigital number, since it uses as much as digits as its factorization.

2108681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7050.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 2108681 is about 1452.1298151336. The cubic root of 2108681 is about 128.2341295892.

The spelling of 2108681 in words is "two million, one hundred eight thousand, six hundred eighty-one".