491656663 has 2 divisors, whose sum is σ = 491656664. Its totient is φ = 491656662.

The previous prime is 491656657. The next prime is 491656709. The reversal of 491656663 is 366656194.

It is an a-pointer prime, because the next prime (491656709) can be obtained adding 491656663 to its sum of digits (46).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491656663 - 2⁵ = 491656631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491651663) 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, 245828331 + 245828332.

It is an arithmetic number, because the mean of its divisors is an integer number (245828332).

Almost surely, 2^491656663 is an apocalyptic number.

491656663 is a deficient number, since it is larger than the sum of its proper divisors (1).

491656663 is an equidigital number, since it uses as much as digits as its factorization.

491656663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 46.

The square root of 491656663 is about 22173.3322484466. The cubic root of 491656663 is about 789.2609993562.

The spelling of 491656663 in words is "four hundred ninety-one million, six hundred fifty-six thousand, six hundred sixty-three".