165565747565161 has 2 divisors, whose sum is σ = 165565747565162. Its totient is φ = 165565747565160.

The previous prime is 165565747565149. The next prime is 165565747565167. The reversal of 165565747565161 is 161565747565561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129383345102400 + 36182402462761 = 11374680^2 + 6015181^2 .

It is a cyclic number.

It is not a de Polignac number, because 165565747565161 - 2⁷ = 165565747565033 is a prime.

It is not a weakly prime, because it can be changed into another prime (165565747565167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82782873782580 + 82782873782581.

It is an arithmetic number, because the mean of its divisors is an integer number (82782873782581).

Almost surely, 2^{165565747565161} is an apocalyptic number.

It is an amenable number.

165565747565161 is a deficient number, since it is larger than the sum of its proper divisors (1).

165565747565161 is an equidigital number, since it uses as much as digits as its factorization.

165565747565161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 793800000, while the sum is 70.

The spelling of 165565747565161 in words is "one hundred sixty-five trillion, five hundred sixty-five billion, seven hundred forty-seven million, five hundred sixty-five thousand, one hundred sixty-one".