491393218 has 8 divisors (see below), whose sum is σ = 737538048. Its totient is φ = 245547204.

The previous prime is 491393153. The next prime is 491393237. The reversal of 491393218 is 812393194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 70546 + ... + 77197.

It is an arithmetic number, because the mean of its divisors is an integer number (92192256).

Almost surely, 2^491393218 is an apocalyptic number.

491393218 is a deficient number, since it is larger than the sum of its proper divisors (246144830).

491393218 is a wasteful number, since it uses less digits than its factorization.

491393218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149408.

The product of its digits is 46656, while the sum is 40.

The square root of 491393218 is about 22167.3908703753. The cubic root of 491393218 is about 789.1200039363.

The spelling of 491393218 in words is "four hundred ninety-one million, three hundred ninety-three thousand, two hundred eighteen".