18322078777 has 2 divisors, whose sum is σ = 18322078778. Its totient is φ = 18322078776.

The previous prime is 18322078721. The next prime is 18322078781. The reversal of 18322078777 is 77787022381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11086194681 + 7235884096 = 105291^2 + 85064^2 .

It is an emirp because it is prime and its reverse (77787022381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18322078777 is a prime.

It is not a weakly prime, because it can be changed into another prime (18322078787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9161039388 + 9161039389.

It is an arithmetic number, because the mean of its divisors is an integer number (9161039389).

Almost surely, 2^18322078777 is an apocalyptic number.

It is an amenable number.

18322078777 is a deficient number, since it is larger than the sum of its proper divisors (1).

18322078777 is an equidigital number, since it uses as much as digits as its factorization.

18322078777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1843968, while the sum is 52.

The spelling of 18322078777 in words is "eighteen billion, three hundred twenty-two million, seventy-eight thousand, seven hundred seventy-seven".