6918815385 has 12 divisors (see below), whose sum is σ = 11992613412. Its totient is φ = 3690034848.

The previous prime is 6918815377. The next prime is 6918815399. The reversal of 6918815385 is 5835188196.

It can be written as a sum of positive squares in 2 ways, for example, as 3681091584 + 3237723801 = 60672^2 + 56901^2 .

It is not a de Polignac number, because 6918815385 - 2³ = 6918815377 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76875682 + ... + 76875771.

It is an arithmetic number, because the mean of its divisors is an integer number (999384451).

Almost surely, 2^6918815385 is an apocalyptic number.

It is an amenable number.

6918815385 is a deficient number, since it is larger than the sum of its proper divisors (5073798027).

6918815385 is a wasteful number, since it uses less digits than its factorization.

6918815385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153751464 (or 153751461 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 54.

The square root of 6918815385 is about 83179.4168349358. The cubic root of 6918815385 is about 1905.5071417266.

The spelling of 6918815385 in words is "six billion, nine hundred eighteen million, eight hundred fifteen thousand, three hundred eighty-five".