18000039000821 has 2 divisors, whose sum is σ = 18000039000822. Its totient is φ = 18000039000820.

The previous prime is 18000039000781. The next prime is 18000039000883. The reversal of 18000039000821 is 12800093000081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13876824475921 + 4123214524900 = 3725161^2 + 2030570^2 .

It is an emirp because it is prime and its reverse (12800093000081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18000039000821 - 2³⁴ = 17982859131637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18000039005821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000019500410 + 9000019500411.

It is an arithmetic number, because the mean of its divisors is an integer number (9000019500411).

Almost surely, 2^{18000039000821} is an apocalyptic number.

It is an amenable number.

18000039000821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18000039000821 is an equidigital number, since it uses as much as digits as its factorization.

18000039000821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 32.

The spelling of 18000039000821 in words is "eighteen trillion, thirty-nine million, eight hundred twenty-one", and thus it is an aban number.