18978710846761 has 2 divisors, whose sum is σ = 18978710846762. Its totient is φ = 18978710846760.

The previous prime is 18978710846717. The next prime is 18978710846773. The reversal of 18978710846761 is 16764801787981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18769308510736 + 209402336025 = 4332356^2 + 457605^2 .

It is a cyclic number.

It is not a de Polignac number, because 18978710846761 - 2²³ = 18978702458153 is a prime.

It is a super-2 number, since 2×18978710846761² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18978710844761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9489355423380 + 9489355423381.

It is an arithmetic number, because the mean of its divisors is an integer number (9489355423381).

Almost surely, 2^{18978710846761} is an apocalyptic number.

It is an amenable number.

18978710846761 is a deficient number, since it is larger than the sum of its proper divisors (1).

18978710846761 is an equidigital number, since it uses as much as digits as its factorization.

18978710846761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 227598336, while the sum is 73.

The spelling of 18978710846761 in words is "eighteen trillion, nine hundred seventy-eight billion, seven hundred ten million, eight hundred forty-six thousand, seven hundred sixty-one".