491211839 has 2 divisors, whose sum is σ = 491211840. Its totient is φ = 491211838.

The previous prime is 491211829. The next prime is 491211881. The reversal of 491211839 is 938112194.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491211839 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491211829) 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 as a sum of consecutive naturals, namely, 245605919 + 245605920.

It is an arithmetic number, because the mean of its divisors is an integer number (245605920).

Almost surely, 2^491211839 is an apocalyptic number.

491211839 is a deficient number, since it is larger than the sum of its proper divisors (1).

491211839 is an equidigital number, since it uses as much as digits as its factorization.

491211839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 491211839 is about 22163.2993708067. The cubic root of 491211839 is about 789.0229008385.

The spelling of 491211839 in words is "four hundred ninety-one million, two hundred eleven thousand, eight hundred thirty-nine".