18484868021 has 2 divisors, whose sum is σ = 18484868022. Its totient is φ = 18484868020.

The previous prime is 18484867987. The next prime is 18484868063. The reversal of 18484868021 is 12086848481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18201787396 + 283080625 = 134914^2 + 16825^2 .

It is an emirp because it is prime and its reverse (12086848481) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18484868021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18484868071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9242434010 + 9242434011.

It is an arithmetic number, because the mean of its divisors is an integer number (9242434011).

Almost surely, 2^18484868021 is an apocalyptic number.

It is an amenable number.

18484868021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18484868021 is an equidigital number, since it uses as much as digits as its factorization.

18484868021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 786432, while the sum is 50.

The spelling of 18484868021 in words is "eighteen billion, four hundred eighty-four million, eight hundred sixty-eight thousand, twenty-one".