18364616021 has 2 divisors, whose sum is σ = 18364616022. Its totient is φ = 18364616020.

The previous prime is 18364615979. The next prime is 18364616047. The reversal of 18364616021 is 12061646381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18147053521 + 217562500 = 134711^2 + 14750^2 .

It is a cyclic number.

It is not a de Polignac number, because 18364616021 - 2⁶ = 18364615957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18364616071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9182308010 + 9182308011.

It is an arithmetic number, because the mean of its divisors is an integer number (9182308011).

Almost surely, 2^18364616021 is an apocalyptic number.

It is an amenable number.

18364616021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18364616021 is an equidigital number, since it uses as much as digits as its factorization.

18364616021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 38.

The spelling of 18364616021 in words is "eighteen billion, three hundred sixty-four million, six hundred sixteen thousand, twenty-one".