18518335016661 has 6 divisors (see below), whose sum is σ = 26748706135190. Its totient is φ = 12345556677768.

The previous prime is 18518335016647. The next prime is 18518335016743. The reversal of 18518335016661 is 16661053381581.

It can be written as a sum of positive squares in only one way, i.e., 17932641743025 + 585693273636 = 4234695^2 + 765306^2 .

It is not a de Polignac number, because 18518335016661 - 2²⁵ = 18518301462229 is a prime.

It is a super-3 number, since 3×18518335016661³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18518335016598 and 18518335016607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18518335036661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1028796389806 + ... + 1028796389823.

Almost surely, 2^{18518335016661} is an apocalyptic number.

It is an amenable number.

18518335016661 is a deficient number, since it is larger than the sum of its proper divisors (8230371118529).

18518335016661 is a wasteful number, since it uses less digits than its factorization.

18518335016661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2057592779635 (or 2057592779632 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The spelling of 18518335016661 in words is "eighteen trillion, five hundred eighteen billion, three hundred thirty-five million, sixteen thousand, six hundred sixty-one".