165844661 has 2 divisors, whose sum is σ = 165844662. Its totient is φ = 165844660.

The previous prime is 165844643. The next prime is 165844681. The reversal of 165844661 is 166448561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132135025 + 33709636 = 11495^2 + 5806^2 .

It is a cyclic number.

It is not a de Polignac number, because 165844661 - 2¹⁴ = 165828277 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 (165844681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82922330 + 82922331.

It is an arithmetic number, because the mean of its divisors is an integer number (82922331).

Almost surely, 2^165844661 is an apocalyptic number.

It is an amenable number.

165844661 is a deficient number, since it is larger than the sum of its proper divisors (1).

165844661 is an equidigital number, since it uses as much as digits as its factorization.

165844661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 138240, while the sum is 41.

The square root of 165844661 is about 12878.0689934477. The cubic root of 165844661 is about 549.4149823636.

The spelling of 165844661 in words is "one hundred sixty-five million, eight hundred forty-four thousand, six hundred sixty-one".