12815181 has 6 divisors (see below), whose sum is σ = 18510830. Its totient is φ = 8543448.

The previous prime is 12815171. The next prime is 12815191. The reversal of 12815181 is 18151821.

12815181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (12815171) and next prime (12815191).

It can be written as a sum of positive squares in only one way, i.e., 6734025 + 6081156 = 2595^2 + 2466^2 .

It is not a de Polignac number, because 12815181 - 2⁵ = 12815149 is a prime.

It is a super-2 number, since 2×12815181² = 328457728125522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12815111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 711946 + ... + 711963.

Almost surely, 2^12815181 is an apocalyptic number.

It is an amenable number.

12815181 is a deficient number, since it is larger than the sum of its proper divisors (5695649).

12815181 is a wasteful number, since it uses less digits than its factorization.

12815181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423915 (or 1423912 counting only the distinct ones).

The product of its digits is 640, while the sum is 27.

The square root of 12815181 is about 3579.8297445549. The cubic root of 12815181 is about 234.0138606736.

It can be divided in two parts, 12815 and 181, that added together give a square (12996 = 114²).

The spelling of 12815181 in words is "twelve million, eight hundred fifteen thousand, one hundred eighty-one".