18218536172813 has 8 divisors (see below), whose sum is σ = 18239844883128. Its totient is φ = 18197234567424.

The previous prime is 18218536172797. The next prime is 18218536172831. The reversal of 18218536172813 is 31827163581281.

It can be written as a sum of positive squares in 4 ways, for example, as 11806185336169 + 6412350836644 = 3436013^2 + 2532262^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18218536172813 - 2⁴ = 18218536172797 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 (18218536172873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3363881 + ... + 6910337.

It is an arithmetic number, because the mean of its divisors is an integer number (2279980610391).

Almost surely, 2^{18218536172813} is an apocalyptic number.

It is an amenable number.

18218536172813 is a deficient number, since it is larger than the sum of its proper divisors (21308710315).

18218536172813 is a wasteful number, since it uses less digits than its factorization.

18218536172813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3552463.

The product of its digits is 3870720, while the sum is 56.

The spelling of 18218536172813 in words is "eighteen trillion, two hundred eighteen billion, five hundred thirty-six million, one hundred seventy-two thousand, eight hundred thirteen".