18515948378 has 8 divisors (see below), whose sum is σ = 29407682772. Its totient is φ = 8713387456.

The previous prime is 18515948329. The next prime is 18515948447. The reversal of 18515948378 is 87384951581.

It can be written as a sum of positive squares in 2 ways, for example, as 18401736409 + 114211969 = 135653^2 + 10687^2 .

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

It is an unprimeable number.

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, 272293325 + ... + 272293392.

Almost surely, 2^18515948378 is an apocalyptic number.

18515948378 is a deficient number, since it is larger than the sum of its proper divisors (10891734394).

18515948378 is a wasteful number, since it uses less digits than its factorization.

18515948378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544586736.

The product of its digits is 9676800, while the sum is 59.

The spelling of 18515948378 in words is "eighteen billion, five hundred fifteen million, nine hundred forty-eight thousand, three hundred seventy-eight".