491785911 has 40 divisors (see below), whose sum is σ = 818840880. Its totient is φ = 292315392.

The previous prime is 491785909. The next prime is 491785919. The reversal of 491785911 is 119587194.

It is a happy number.

491785911 is a `hidden beast` number, since 49 + 17 + 8 + 591 + 1 = 666.

It is not a de Polignac number, because 491785911 - 2¹ = 491785909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491785919) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 16765 + ... + 35561.

It is an arithmetic number, because the mean of its divisors is an integer number (20471022).

Almost surely, 2^491785911 is an apocalyptic number.

491785911 is a deficient number, since it is larger than the sum of its proper divisors (327054969).

491785911 is a wasteful number, since it uses less digits than its factorization.

491785911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18845 (or 18836 counting only the distinct ones).

The product of its digits is 90720, while the sum is 45.

The square root of 491785911 is about 22176.2465489541. The cubic root of 491785911 is about 789.3301543009.

The spelling of 491785911 in words is "four hundred ninety-one million, seven hundred eighty-five thousand, nine hundred eleven".