18681155659 has 4 divisors (see below), whose sum is σ = 19078627104. Its totient is φ = 18283684216.

The previous prime is 18681155639. The next prime is 18681155677. The reversal of 18681155659 is 95655118681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95655118681 = 2917 ⋅32792293.

It is a cyclic number.

It is not a de Polignac number, because 18681155659 - 2¹¹ = 18681153611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18681155639) 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, 198735652 + ... + 198735745.

It is an arithmetic number, because the mean of its divisors is an integer number (4769656776).

Almost surely, 2^18681155659 is an apocalyptic number.

18681155659 is a deficient number, since it is larger than the sum of its proper divisors (397471445).

18681155659 is an equidigital number, since it uses as much as digits as its factorization.

18681155659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397471444.

The product of its digits is 2592000, while the sum is 55.

The spelling of 18681155659 in words is "eighteen billion, six hundred eighty-one million, one hundred fifty-five thousand, six hundred fifty-nine".