161668664771 has 2 divisors, whose sum is σ = 161668664772. Its totient is φ = 161668664770.

The previous prime is 161668664723. The next prime is 161668664821. The reversal of 161668664771 is 177466866161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161668664771 - 2¹⁸ = 161668402627 is a prime.

It is a super-2 number, since 2×161668664771² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161668664771.

It is not a weakly prime, because it can be changed into another prime (161668664471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80834332385 + 80834332386.

It is an arithmetic number, because the mean of its divisors is an integer number (80834332386).

Almost surely, 2^161668664771 is an apocalyptic number.

161668664771 is a deficient number, since it is larger than the sum of its proper divisors (1).

161668664771 is an equidigital number, since it uses as much as digits as its factorization.

161668664771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12192768, while the sum is 59.

The spelling of 161668664771 in words is "one hundred sixty-one billion, six hundred sixty-eight million, six hundred sixty-four thousand, seven hundred seventy-one".