18726847681 has 4 divisors (see below), whose sum is σ = 18727531264. Its totient is φ = 18726164100.

The previous prime is 18726847673. The next prime is 18726847723. The reversal of 18726847681 is 18674862781.

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 18726847681 - 2³ = 18726847673 is a prime.

It is a super-2 number, since 2×18726847681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18726847631) 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, 298905 + ... + 356086.

It is an arithmetic number, because the mean of its divisors is an integer number (4681882816).

Almost surely, 2^18726847681 is an apocalyptic number.

It is an amenable number.

18726847681 is a deficient number, since it is larger than the sum of its proper divisors (683583).

18726847681 is an equidigital number, since it uses as much as digits as its factorization.

18726847681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683582.

The product of its digits is 7225344, while the sum is 58.

The spelling of 18726847681 in words is "eighteen billion, seven hundred twenty-six million, eight hundred forty-seven thousand, six hundred eighty-one".