491685783 has 4 divisors (see below), whose sum is σ = 655581048. Its totient is φ = 327790520.

The previous prime is 491685773. The next prime is 491685791. The reversal of 491685783 is 387586194.

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

It is a cyclic number.

It is not a de Polignac number, because 491685783 - 2⁴ = 491685767 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491685773) 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 3 ways as a sum of consecutive naturals, for example, 81947628 + ... + 81947633.

It is an arithmetic number, because the mean of its divisors is an integer number (163895262).

Almost surely, 2^491685783 is an apocalyptic number.

491685783 is a deficient number, since it is larger than the sum of its proper divisors (163895265).

491685783 is a wasteful number, since it uses less digits than its factorization.

491685783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163895264.

The product of its digits is 1451520, while the sum is 51.

The square root of 491685783 is about 22173.9888833741. The cubic root of 491685783 is about 789.2765812505.

The spelling of 491685783 in words is "four hundred ninety-one million, six hundred eighty-five thousand, seven hundred eighty-three".