78180377761 has 2 divisors, whose sum is σ = 78180377762. Its totient is φ = 78180377760.

The previous prime is 78180377749. The next prime is 78180377789. The reversal of 78180377761 is 16777308187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39742814736 + 38437563025 = 199356^2 + 196055^2 .

It is an emirp because it is prime and its reverse (16777308187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78180377761 - 2⁷ = 78180377633 is a prime.

It is a super-2 number, since 2×78180377761² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78180377861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39090188880 + 39090188881.

It is an arithmetic number, because the mean of its divisors is an integer number (39090188881).

Almost surely, 2^78180377761 is an apocalyptic number.

It is an amenable number.

78180377761 is a deficient number, since it is larger than the sum of its proper divisors (1).

78180377761 is an equidigital number, since it uses as much as digits as its factorization.

78180377761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2765952, while the sum is 55.

The spelling of 78180377761 in words is "seventy-eight billion, one hundred eighty million, three hundred seventy-seven thousand, seven hundred sixty-one".