491281218 has 24 divisors (see below), whose sum is σ = 1071497856. Its totient is φ = 162675000.

The previous prime is 491281169. The next prime is 491281237. The reversal of 491281218 is 812182194.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87658 + ... + 93093.

It is an arithmetic number, because the mean of its divisors is an integer number (44645744).

Almost surely, 2^491281218 is an apocalyptic number.

491281218 is an abundant number, since it is smaller than the sum of its proper divisors (580216638).

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

491281218 is a wasteful number, since it uses less digits than its factorization.

491281218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180910 (or 180907 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 491281218 is about 22164.8644931567. The cubic root of 491281218 is about 789.0600464163.

The spelling of 491281218 in words is "four hundred ninety-one million, two hundred eighty-one thousand, two hundred eighteen".