18427686785 has 4 divisors (see below), whose sum is σ = 22113224148. Its totient is φ = 14742149424.

The previous prime is 18427686743. The next prime is 18427686787. The reversal of 18427686785 is 58768672481.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6687314176 + 11740372609 = 81776^2 + 108353^2 .

It is a cyclic number.

It is not a de Polignac number, because 18427686785 - 2⁶ = 18427686721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18427686787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1842768674 + ... + 1842768683.

It is an arithmetic number, because the mean of its divisors is an integer number (5528306037).

Almost surely, 2^18427686785 is an apocalyptic number.

It is an amenable number.

18427686785 is a deficient number, since it is larger than the sum of its proper divisors (3685537363).

18427686785 is an equidigital number, since it uses as much as digits as its factorization.

18427686785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3685537362.

The product of its digits is 36126720, while the sum is 62.

The spelling of 18427686785 in words is "eighteen billion, four hundred twenty-seven million, six hundred eighty-six thousand, seven hundred eighty-five".