18243577687 has 4 divisors (see below), whose sum is σ = 18262444816. Its totient is φ = 18224710560.

The previous prime is 18243577673. The next prime is 18243577721. The reversal of 18243577687 is 78677534281.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18243577687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18243577657) 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, 9432114 + ... + 9434047.

It is an arithmetic number, because the mean of its divisors is an integer number (4565611204).

Almost surely, 2^18243577687 is an apocalyptic number.

18243577687 is a deficient number, since it is larger than the sum of its proper divisors (18867129).

18243577687 is an equidigital number, since it uses as much as digits as its factorization.

18243577687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18867128.

The product of its digits is 15805440, while the sum is 58.

The spelling of 18243577687 in words is "eighteen billion, two hundred forty-three million, five hundred seventy-seven thousand, six hundred eighty-seven".