18056398687 has 4 divisors (see below), whose sum is σ = 19006735480. Its totient is φ = 17106061896.

The previous prime is 18056398681. The next prime is 18056398691. The reversal of 18056398687 is 78689365081.

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

It is a cyclic number.

It is not a de Polignac number, because 18056398687 - 2¹⁹ = 18055874399 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 (18056398681) 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, 475168368 + ... + 475168405.

It is an arithmetic number, because the mean of its divisors is an integer number (4751683870).

Almost surely, 2^18056398687 is an apocalyptic number.

18056398687 is a deficient number, since it is larger than the sum of its proper divisors (950336793).

18056398687 is an equidigital number, since it uses as much as digits as its factorization.

18056398687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950336792.

The product of its (nonzero) digits is 17418240, while the sum is 61.

The spelling of 18056398687 in words is "eighteen billion, fifty-six million, three hundred ninety-eight thousand, six hundred eighty-seven".