161665110569 has 2 divisors, whose sum is σ = 161665110570. Its totient is φ = 161665110568.

The previous prime is 161665110547. The next prime is 161665110587. The reversal of 161665110569 is 965011566161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161503515625 + 161594944 = 401875^2 + 12712^2 .

It is a cyclic number.

It is not a de Polignac number, because 161665110569 - 2¹⁶ = 161665045033 is a prime.

It is a super-2 number, since 2×161665110569² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161665110599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80832555284 + 80832555285.

It is an arithmetic number, because the mean of its divisors is an integer number (80832555285).

Almost surely, 2^161665110569 is an apocalyptic number.

It is an amenable number.

161665110569 is a deficient number, since it is larger than the sum of its proper divisors (1).

161665110569 is an equidigital number, since it uses as much as digits as its factorization.

161665110569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 291600, while the sum is 47.

The spelling of 161665110569 in words is "one hundred sixty-one billion, six hundred sixty-five million, one hundred ten thousand, five hundred sixty-nine".