18516833516661 has 4 divisors (see below), whose sum is σ = 24689111355552. Its totient is φ = 12344555677772.

The previous prime is 18516833516651. The next prime is 18516833516683. The reversal of 18516833516661 is 16661533861581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18516833516661 - 2⁹ = 18516833516149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18516833516595 and 18516833516604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18516833516651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3086138919441 + ... + 3086138919446.

It is an arithmetic number, because the mean of its divisors is an integer number (6172277838888).

Almost surely, 2^{18516833516661} is an apocalyptic number.

It is an amenable number.

18516833516661 is a deficient number, since it is larger than the sum of its proper divisors (6172277838891).

18516833516661 is an equidigital number, since it uses as much as digits as its factorization.

18516833516661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6172277838890.

The product of its digits is 18662400, while the sum is 60.

The spelling of 18516833516661 in words is "eighteen trillion, five hundred sixteen billion, eight hundred thirty-three million, five hundred sixteen thousand, six hundred sixty-one".