491813868 has 96 divisors (see below), whose sum is σ = 1430517760. Its totient is φ = 128044800.

The previous prime is 491813863. The next prime is 491813873. The reversal of 491813868 is 868318194.

It is an interprime number because it is at equal distance from previous prime (491813863) and next prime (491813873).

It is not an unprimeable number, because it can be changed into a prime (491813863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 83418 + ... + 89118.

Almost surely, 2^491813868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491813868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (715258880).

491813868 is an abundant number, since it is smaller than the sum of its proper divisors (938703892).

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

491813868 is a wasteful number, since it uses less digits than its factorization.

491813868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5807 (or 5805 counting only the distinct ones).

The product of its digits is 331776, while the sum is 48.

The square root of 491813868 is about 22176.8768766028. The cubic root of 491813868 is about 789.3451112733.

The spelling of 491813868 in words is "four hundred ninety-one million, eight hundred thirteen thousand, eight hundred sixty-eight".