1665841 has 2 divisors, whose sum is σ = 1665842. Its totient is φ = 1665840.

The previous prime is 1665827. The next prime is 1665869. The reversal of 1665841 is 1485661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1449616 + 216225 = 1204^2 + 465^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665841 - 2¹¹ = 1663793 is a prime.

It is not a weakly prime, because it can be changed into another prime (1665941) 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, 832920 + 832921.

It is an arithmetic number, because the mean of its divisors is an integer number (832921).

2^1665841 is an apocalyptic number.

It is an amenable number.

1665841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665841 is an equidigital number, since it uses as much as digits as its factorization.

1665841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 31.

The square root of 1665841 is about 1290.6746297964. The cubic root of 1665841 is about 118.5435281941.

The spelling of 1665841 in words is "one million, six hundred sixty-five thousand, eight hundred forty-one".