491788664 has 8 divisors (see below), whose sum is σ = 922103760. Its totient is φ = 245894328.

The previous prime is 491788651. The next prime is 491788669. The reversal of 491788664 is 466887194.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491788669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30736784 + ... + 30736799.

It is an arithmetic number, because the mean of its divisors is an integer number (115262970).

Almost surely, 2^491788664 is an apocalyptic number.

It is an amenable number.

491788664 is a deficient number, since it is larger than the sum of its proper divisors (430315096).

491788664 is a wasteful number, since it uses less digits than its factorization.

491788664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61473589 (or 61473585 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 53.

The square root of 491788664 is about 22176.3086197861. The cubic root of 491788664 is about 789.3316271788.

The spelling of 491788664 in words is "four hundred ninety-one million, seven hundred eighty-eight thousand, six hundred sixty-four".