161665711 has 2 divisors, whose sum is σ = 161665712. Its totient is φ = 161665710.

The previous prime is 161665697. The next prime is 161665783. The reversal of 161665711 is 117566161.

It is a weak prime.

It is an emirp because it is prime and its reverse (117566161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161665711 - 2⁹ = 161665199 is a prime.

It is a super-2 number, since 2×161665711² = 52271604226271042, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161665811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80832855 + 80832856.

It is an arithmetic number, because the mean of its divisors is an integer number (80832856).

Almost surely, 2^161665711 is an apocalyptic number.

161665711 is a deficient number, since it is larger than the sum of its proper divisors (1).

161665711 is an equidigital number, since it uses as much as digits as its factorization.

161665711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 34.

The square root of 161665711 is about 12714.7831676360. The cubic root of 161665711 is about 544.7609545608.

The spelling of 161665711 in words is "one hundred sixty-one million, six hundred sixty-five thousand, seven hundred eleven".