491678218 has 4 divisors (see below), whose sum is σ = 737517330. Its totient is φ = 245839108.

The previous prime is 491678203. The next prime is 491678261. The reversal of 491678218 is 812876194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 311769649 + 179908569 = 17657^2 + 13413^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122919553 + ... + 122919556.

Almost surely, 2^491678218 is an apocalyptic number.

491678218 is a deficient number, since it is larger than the sum of its proper divisors (245839112).

491678218 is a wasteful number, since it uses less digits than its factorization.

491678218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245839111.

The product of its digits is 193536, while the sum is 46.

The square root of 491678218 is about 22173.8182999681. The cubic root of 491678218 is about 789.2725333347.

The spelling of 491678218 in words is "four hundred ninety-one million, six hundred seventy-eight thousand, two hundred eighteen".