1665161 has 2 divisors, whose sum is σ = 1665162. Its totient is φ = 1665160.

The previous prime is 1665149. The next prime is 1665173. The reversal of 1665161 is 1615661.

It is a balanced prime because it is at equal distance from previous prime (1665149) and next prime (1665173).

It can be written as a sum of positive squares in only one way, i.e., 1394761 + 270400 = 1181^2 + 520^2 .

It is an emirp because it is prime and its reverse (1615661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1665161 is a prime.

It is a super-2 number, since 2×1665161² = 5545522311842, which contains 22 as substring.

It is a Sophie Germain prime.

It is an Ulam 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 1665161.

It is not a weakly prime, because it can be changed into another prime (1665121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832580 + 832581.

It is an arithmetic number, because the mean of its divisors is an integer number (832581).

2^1665161 is an apocalyptic number.

It is an amenable number.

1665161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665161 is an equidigital number, since it uses as much as digits as its factorization.

1665161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 26.

The square root of 1665161 is about 1290.4111747811. The cubic root of 1665161 is about 118.5273960882.

The spelling of 1665161 in words is "one million, six hundred sixty-five thousand, one hundred sixty-one".