18518335000021 has 2 divisors, whose sum is σ = 18518335000022. Its totient is φ = 18518335000020.

The previous prime is 18518334999953. The next prime is 18518335000103. The reversal of 18518335000021 is 12000053381581.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12507433462225 + 6010901537796 = 3536585^2 + 2451714^2 .

It is a cyclic number.

It is not a de Polignac number, because 18518335000021 - 2¹⁷ = 18518334868949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18518335040021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9259167500010 + 9259167500011.

It is an arithmetic number, because the mean of its divisors is an integer number (9259167500011).

Almost surely, 2^{18518335000021} is an apocalyptic number.

It is an amenable number.

18518335000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18518335000021 is an equidigital number, since it uses as much as digits as its factorization.

18518335000021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 18518335000021 in words is "eighteen trillion, five hundred eighteen billion, three hundred thirty-five million, twenty-one", and thus it is an aban number.