491117018397 has 16 divisors (see below), whose sum is σ = 664007292480. Its totient is φ = 322821942912.

The previous prime is 491117018393. The next prime is 491117018419. The reversal of 491117018397 is 793810711194.

It is not a de Polignac number, because 491117018397 - 2² = 491117018393 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491117018393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320218 + ... + 1041524.

It is an arithmetic number, because the mean of its divisors is an integer number (41500455780).

Almost surely, 2^491117018397 is an apocalyptic number.

It is an amenable number.

491117018397 is a deficient number, since it is larger than the sum of its proper divisors (172890274083).

491117018397 is a wasteful number, since it uses less digits than its factorization.

491117018397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724492.

The product of its (nonzero) digits is 381024, while the sum is 51.

The spelling of 491117018397 in words is "four hundred ninety-one billion, one hundred seventeen million, eighteen thousand, three hundred ninety-seven".