2105681 has 2 divisors, whose sum is σ = 2105682. Its totient is φ = 2105680.

The previous prime is 2105669. The next prime is 2105693. The reversal of 2105681 is 1865012.

It is a balanced prime because it is at equal distance from previous prime (2105669) and next prime (2105693).

It can be written as a sum of positive squares in only one way, i.e., 1123600 + 982081 = 1060^2 + 991^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105681 - 2¹⁰ = 2104657 is a prime.

It is a super-2 number, since 2×2105681² = 8867784947522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2105611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1052840 + 1052841.

It is an arithmetic number, because the mean of its divisors is an integer number (1052841).

2^2105681 is an apocalyptic number.

It is an amenable number.

2105681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2105681 is an equidigital number, since it uses as much as digits as its factorization.

2105681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 2105681 is about 1451.0964819749. The cubic root of 2105681 is about 128.1732882432.

The spelling of 2105681 in words is "two million, one hundred five thousand, six hundred eighty-one".