18555565557013 has 4 divisors (see below), whose sum is σ = 19532174270560. Its totient is φ = 17578956843468.

The previous prime is 18555565556971. The next prime is 18555565557043. The reversal of 18555565557013 is 31075556555581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18555565557013 - 2⁹ = 18555565556501 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 (18555565557043) 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, 488304356745 + ... + 488304356782.

It is an arithmetic number, because the mean of its divisors is an integer number (4883043567640).

Almost surely, 2^{18555565557013} is an apocalyptic number.

It is an amenable number.

18555565557013 is a deficient number, since it is larger than the sum of its proper divisors (976608713547).

18555565557013 is an equidigital number, since it uses as much as digits as its factorization.

18555565557013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976608713546.

The product of its (nonzero) digits is 78750000, while the sum is 61.

The spelling of 18555565557013 in words is "eighteen trillion, five hundred fifty-five billion, five hundred sixty-five million, five hundred fifty-seven thousand, thirteen".