491638727 has 2 divisors, whose sum is σ = 491638728. Its totient is φ = 491638726.

The previous prime is 491638669. The next prime is 491638729. The reversal of 491638727 is 727836194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491638727 - 2¹⁴ = 491622343 is a prime.

Together with 491638729, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491638729) 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, 245819363 + 245819364.

It is an arithmetic number, because the mean of its divisors is an integer number (245819364).

Almost surely, 2^491638727 is an apocalyptic number.

491638727 is a deficient number, since it is larger than the sum of its proper divisors (1).

491638727 is an equidigital number, since it uses as much as digits as its factorization.

491638727 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 47.

The square root of 491638727 is about 22172.9277949485. The cubic root of 491638727 is about 789.2514016304.

The spelling of 491638727 in words is "four hundred ninety-one million, six hundred thirty-eight thousand, seven hundred twenty-seven".