18768686781 has 8 divisors (see below), whose sum is σ = 26949909280. Its totient is φ = 11549961072.

The previous prime is 18768686777. The next prime is 18768686819.

It is a happy number.

18768686781 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18768686781 - 2² = 18768686777 is a prime.

It is a super-2 number, since 2×18768686781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18768686701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240624151 + ... + 240624228.

It is an arithmetic number, because the mean of its divisors is an integer number (3368738660).

Almost surely, 2^18768686781 is an apocalyptic number.

It is an amenable number.

18768686781 is a deficient number, since it is larger than the sum of its proper divisors (8181222499).

18768686781 is a wasteful number, since it uses less digits than its factorization.

18768686781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481248395.

The product of its digits is 43352064, while the sum is 66.

The spelling of 18768686781 in words is "eighteen billion, seven hundred sixty-eight million, six hundred eighty-six thousand, seven hundred eighty-one".