18505776163 has 4 divisors (see below), whose sum is σ = 21149458480. Its totient is φ = 15862093848.

The previous prime is 18505776137. The next prime is 18505776169. The reversal of 18505776163 is 36167750581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36167750581 = 1499 ⋅24127919.

It is a cyclic number.

It is not a de Polignac number, because 18505776163 - 2⁵ = 18505776131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18505776169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1321841148 + ... + 1321841161.

It is an arithmetic number, because the mean of its divisors is an integer number (5287364620).

Almost surely, 2^18505776163 is an apocalyptic number.

18505776163 is a deficient number, since it is larger than the sum of its proper divisors (2643682317).

18505776163 is an equidigital number, since it uses as much as digits as its factorization.

18505776163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2643682316.

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 18505776163 in words is "eighteen billion, five hundred five million, seven hundred seventy-six thousand, one hundred sixty-three".