491702977857 has 128 divisors (see below), whose sum is σ = 827318861824. Its totient is φ = 252907619328.

The previous prime is 491702977853. The next prime is 491702977867. The reversal of 491702977857 is 758779207194.

It is not a de Polignac number, because 491702977857 - 2² = 491702977853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491702977853) 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 in 127 ways as a sum of consecutive naturals, for example, 560664303 + ... + 560665179.

It is an arithmetic number, because the mean of its divisors is an integer number (6463428608).

Almost surely, 2^491702977857 is an apocalyptic number.

It is an amenable number.

491702977857 is a deficient number, since it is larger than the sum of its proper divisors (335615883967).

491702977857 is a wasteful number, since it uses less digits than its factorization.

491702977857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287.

The product of its (nonzero) digits is 62233920, while the sum is 66.

The spelling of 491702977857 in words is "four hundred ninety-one billion, seven hundred two million, nine hundred seventy-seven thousand, eight hundred fifty-seven".