81288218 has 32 divisors (see below), whose sum is σ = 139052160. Its totient is φ = 35300160.

The previous prime is 81288217. The next prime is 81288227.

81288218 is nontrivially palindromic in base 10.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81288211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65096 + ... + 66332.

It is an arithmetic number, because the mean of its divisors is an integer number (4345380).

Almost surely, 2^81288218 is an apocalyptic number.

81288218 is a deficient number, since it is larger than the sum of its proper divisors (57763942).

81288218 is a wasteful number, since it uses less digits than its factorization.

81288218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1382.

The product of its digits is 16384, while the sum is 38.

The square root of 81288218 is about 9015.9978926351. The cubic root of 81288218 is about 433.1874516176.

Adding to 81288218 its sum of digits (38), we get a square (81288256 = 9016²).

The spelling of 81288218 in words is "eighty-one million, two hundred eighty-eight thousand, two hundred eighteen".