491918256 has 120 divisors (see below), whose sum is σ = 1497341664. Its totient is φ = 150128640.

The previous prime is 491918173. The next prime is 491918257. The reversal of 491918256 is 652819194.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (491918257) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 87861 + ... + 93291.

Almost surely, 2^491918256 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 491918256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748670832).

491918256 is an abundant number, since it is smaller than the sum of its proper divisors (1005423408).

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

491918256 is a wasteful number, since it uses less digits than its factorization.

491918256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5499 (or 5490 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 491918256 is about 22179.2302842096. The cubic root of 491918256 is about 789.4009537602.

The spelling of 491918256 in words is "four hundred ninety-one million, nine hundred eighteen thousand, two hundred fifty-six".