12818381 has 4 divisors (see below), whose sum is σ = 12931932. Its totient is φ = 12704832.

The previous prime is 12818353. The next prime is 12818387. The reversal of 12818381 is 18381821.

It is a happy number.

12818381 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2353156 + 10465225 = 1534^2 + 3235^2 .

It is a cyclic number.

It is not a de Polignac number, because 12818381 - 2¹⁸ = 12556237 is a prime.

It is a super-2 number, since 2×12818381² = 328621782922322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12818387) 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, 56606 + ... + 56831.

It is an arithmetic number, because the mean of its divisors is an integer number (3232983).

Almost surely, 2^12818381 is an apocalyptic number.

It is an amenable number.

12818381 is a deficient number, since it is larger than the sum of its proper divisors (113551).

12818381 is a wasteful number, since it uses less digits than its factorization.

12818381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113550.

The product of its digits is 3072, while the sum is 32.

The square root of 12818381 is about 3580.2766652872. The cubic root of 12818381 is about 234.0333371064.

The spelling of 12818381 in words is "twelve million, eight hundred eighteen thousand, three hundred eighty-one".