18218536851 has 4 divisors (see below), whose sum is σ = 24291382472. Its totient is φ = 12145691232.

The previous prime is 18218536849. The next prime is 18218536867. The reversal of 18218536851 is 15863581281.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 18218536851 - 2¹ = 18218536849 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18218536851.

It is not an unprimeable number, because it can be changed into a prime (18218536841) 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, 3036422806 + ... + 3036422811.

It is an arithmetic number, because the mean of its divisors is an integer number (6072845618).

Almost surely, 2^18218536851 is an apocalyptic number.

18218536851 is a deficient number, since it is larger than the sum of its proper divisors (6072845621).

18218536851 is an equidigital number, since it uses as much as digits as its factorization.

18218536851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6072845620.

The product of its digits is 460800, while the sum is 48.

The spelling of 18218536851 in words is "eighteen billion, two hundred eighteen million, five hundred thirty-six thousand, eight hundred fifty-one".