218663778503 has 4 divisors (see below), whose sum is σ = 219571097328. Its totient is φ = 217756459680.

The previous prime is 218663778491. The next prime is 218663778523. The reversal of 218663778503 is 305877366812.

218663778503 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 218663778503 - 2²⁶ = 218596669639 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 (218663778523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 453659051 + ... + 453659532.

It is an arithmetic number, because the mean of its divisors is an integer number (54892774332).

Almost surely, 2^218663778503 is an apocalyptic number.

218663778503 is a deficient number, since it is larger than the sum of its proper divisors (907318825).

218663778503 is an equidigital number, since it uses as much as digits as its factorization.

218663778503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907318824.

The product of its (nonzero) digits is 10160640, while the sum is 56.

The spelling of 218663778503 in words is "two hundred eighteen billion, six hundred sixty-three million, seven hundred seventy-eight thousand, five hundred three".