491507811 has 32 divisors (see below), whose sum is σ = 748692480. Its totient is φ = 318528288.

The previous prime is 491507767. The next prime is 491507839. The reversal of 491507811 is 118705194.

It is not a de Polignac number, because 491507811 - 2⁹ = 491507299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491507411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 198000 + ... + 200466.

It is an arithmetic number, because the mean of its divisors is an integer number (23396640).

Almost surely, 2^491507811 is an apocalyptic number.

491507811 is a deficient number, since it is larger than the sum of its proper divisors (257184669).

491507811 is a wasteful number, since it uses less digits than its factorization.

491507811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680 (or 2674 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The square root of 491507811 is about 22169.9754397699. The cubic root of 491507811 is about 789.1813401513.

It can be divided in two parts, 4915078 and 11, that added together give a square (4915089 = 2217²).

The spelling of 491507811 in words is "four hundred ninety-one million, five hundred seven thousand, eight hundred eleven".