491388261768 has 48 divisors (see below), whose sum is σ = 1330915622400. Its totient is φ = 163787174880.

The previous prime is 491388261649. The next prime is 491388261779. The reversal of 491388261768 is 867162883194.

491388261768 is a `hidden beast` number, since 4 + 9 + 1 + 3 + 8 + 8 + 2 + 617 + 6 + 8 = 666.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 1220173 + ... + 1572131.

It is an arithmetic number, because the mean of its divisors is an integer number (27727408800).

Almost surely, 2^491388261768 is an apocalyptic number.

It is an amenable number.

491388261768 is an abundant number, since it is smaller than the sum of its proper divisors (839527360632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491388261768 is a wasteful number, since it uses less digits than its factorization.

491388261768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371362 (or 371355 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 63.

The spelling of 491388261768 in words is "four hundred ninety-one billion, three hundred eighty-eight million, two hundred sixty-one thousand, seven hundred sixty-eight".