81412218 has 24 divisors (see below), whose sum is σ = 186769908. Its totient is φ = 25540992.

The previous prime is 81412217. The next prime is 81412229. The reversal of 81412218 is 81221418.

It can be written as a sum of positive squares in 2 ways, for example, as 75637809 + 5774409 = 8697^2 + 2403^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81412191 and 81412200.

It is not an unprimeable number, because it can be changed into a prime (81412211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 132721 + ... + 133332.

Almost surely, 2^81412218 is an apocalyptic number.

81412218 is an abundant number, since it is smaller than the sum of its proper divisors (105357690).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81412218 is a wasteful number, since it uses less digits than its factorization.

81412218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266078 (or 266075 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 81412218 is about 9022.8719374709. The cubic root of 81412218 is about 433.4076063353.

The spelling of 81412218 in words is "eighty-one million, four hundred twelve thousand, two hundred eighteen".