6918181 has 4 divisors (see below), whose sum is σ = 6923500. Its totient is φ = 6912864.

The previous prime is 6918179. The next prime is 6918187. The reversal of 6918181 is 1818196.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 497025 + 6421156 = 705^2 + 2534^2 .

It is a cyclic number.

It is not a de Polignac number, because 6918181 - 2¹ = 6918179 is a prime.

It is a super-3 number, since 3×6918181³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

6918181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6918187) 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, 745 + ... + 3793.

It is an arithmetic number, because the mean of its divisors is an integer number (1730875).

Almost surely, 2^6918181 is an apocalyptic number.

It is an amenable number.

6918181 is a deficient number, since it is larger than the sum of its proper divisors (5319).

6918181 is a wasteful number, since it uses less digits than its factorization.

6918181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5318.

The product of its digits is 3456, while the sum is 34.

The square root of 6918181 is about 2630.2435248471. The cubic root of 6918181 is about 190.5448901405.

The spelling of 6918181 in words is "six million, nine hundred eighteen thousand, one hundred eighty-one".