1665761 has 2 divisors, whose sum is σ = 1665762. Its totient is φ = 1665760.

The previous prime is 1665757. The next prime is 1665767. The reversal of 1665761 is 1675661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1600225 + 65536 = 1265^2 + 256^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665761 - 2² = 1665757 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665767) 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, 832880 + 832881.

It is an arithmetic number, because the mean of its divisors is an integer number (832881).

2^1665761 is an apocalyptic number.

It is an amenable number.

1665761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665761 is an equidigital number, since it uses as much as digits as its factorization.

1665761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 32.

The square root of 1665761 is about 1290.6436378800. The cubic root of 1665761 is about 118.5416305272.

The spelling of 1665761 in words is "one million, six hundred sixty-five thousand, seven hundred sixty-one".