491386331 has 2 divisors, whose sum is σ = 491386332. Its totient is φ = 491386330.

The previous prime is 491386321. The next prime is 491386333. The reversal of 491386331 is 133683194.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491386331 is a prime.

It is a super-2 number, since 2×491386331² = 482921052587283122, which contains 22 as substring.

Together with 491386333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (491386333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245693165 + 245693166.

It is an arithmetic number, because the mean of its divisors is an integer number (245693166).

Almost surely, 2^491386331 is an apocalyptic number.

491386331 is a deficient number, since it is larger than the sum of its proper divisors (1).

491386331 is an equidigital number, since it uses as much as digits as its factorization.

491386331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 38.

The square root of 491386331 is about 22167.2355290415. The cubic root of 491386331 is about 789.1163173470.

The spelling of 491386331 in words is "four hundred ninety-one million, three hundred eighty-six thousand, three hundred thirty-one".