78806066161 has 2 divisors, whose sum is σ = 78806066162. Its totient is φ = 78806066160.

The previous prime is 78806066147. The next prime is 78806066219. The reversal of 78806066161 is 16166060887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72231937600 + 6574128561 = 268760^2 + 81081^2 .

It is an emirp because it is prime and its reverse (16166060887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78806066161 - 2⁷ = 78806066033 is a prime.

It is not a weakly prime, because it can be changed into another prime (78806066111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39403033080 + 39403033081.

It is an arithmetic number, because the mean of its divisors is an integer number (39403033081).

Almost surely, 2^78806066161 is an apocalyptic number.

It is an amenable number.

78806066161 is a deficient number, since it is larger than the sum of its proper divisors (1).

78806066161 is an equidigital number, since it uses as much as digits as its factorization.

78806066161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 49.

The spelling of 78806066161 in words is "seventy-eight billion, eight hundred six million, sixty-six thousand, one hundred sixty-one".