18394515218 has 8 divisors (see below), whose sum is σ = 27599820348. Its totient is φ = 9194575104.

The previous prime is 18394515211. The next prime is 18394515263. The reversal of 18394515218 is 81251549381.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17826789289 + 567725929 = 133517^2 + 23827^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18394515211) 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, 1332671 + ... + 1346402.

Almost surely, 2^18394515218 is an apocalyptic number.

18394515218 is a deficient number, since it is larger than the sum of its proper divisors (9205305130).

18394515218 is a wasteful number, since it uses less digits than its factorization.

18394515218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682508.

The product of its digits is 345600, while the sum is 47.

The spelling of 18394515218 in words is "eighteen billion, three hundred ninety-four million, five hundred fifteen thousand, two hundred eighteen".