811803218 has 6 divisors (see below), whose sum is σ = 1217765271. Its totient is φ = 405881462.

The previous prime is 811803211. The next prime is 811803221. The reversal of 811803218 is 812308118.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 405901609 + 405901609 = 20147^2 + 20147^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=20147.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811803211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 30221 + ... + 50367.

Almost surely, 2^811803218 is an apocalyptic number.

811803218 is a deficient number, since it is larger than the sum of its proper divisors (405962053).

811803218 is an frugal number, since it uses more digits than its factorization.

811803218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40296 (or 20149 counting only the distinct ones).

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

The square root of 811803218 is about 28492.1606411307. The cubic root of 811803218 is about 932.8609696770.

Multiplying 811803218 by its sum of digits (32), we get a square (25977702976 = 161176²).

The spelling of 811803218 in words is "eight hundred eleven million, eight hundred three thousand, two hundred eighteen".