18966734821 has 2 divisors, whose sum is σ = 18966734822. Its totient is φ = 18966734820.

The previous prime is 18966734771. The next prime is 18966734873. The reversal of 18966734821 is 12843766981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12612413025 + 6354321796 = 112305^2 + 79714^2 .

It is a cyclic number.

It is not a de Polignac number, because 18966734821 - 2¹⁷ = 18966603749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18966734321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9483367410 + 9483367411.

It is an arithmetic number, because the mean of its divisors is an integer number (9483367411).

Almost surely, 2^18966734821 is an apocalyptic number.

It is an amenable number.

18966734821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18966734821 is an equidigital number, since it uses as much as digits as its factorization.

18966734821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 55.

The spelling of 18966734821 in words is "eighteen billion, nine hundred sixty-six million, seven hundred thirty-four thousand, eight hundred twenty-one".