18347452766821 has 2 divisors, whose sum is σ = 18347452766822. Its totient is φ = 18347452766820.

The previous prime is 18347452766813. The next prime is 18347452766843. The reversal of 18347452766821 is 12866725474381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14801063256225 + 3546389510596 = 3847215^2 + 1883186^2 .

It is a cyclic number.

It is not a de Polignac number, because 18347452766821 - 2³ = 18347452766813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18347452761821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9173726383410 + 9173726383411.

It is an arithmetic number, because the mean of its divisors is an integer number (9173726383411).

Almost surely, 2^{18347452766821} is an apocalyptic number.

It is an amenable number.

18347452766821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18347452766821 is an equidigital number, since it uses as much as digits as its factorization.

18347452766821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108380160, while the sum is 64.

The spelling of 18347452766821 in words is "eighteen trillion, three hundred forty-seven billion, four hundred fifty-two million, seven hundred sixty-six thousand, eight hundred twenty-one".