491544913797 has 72 divisors (see below), whose sum is σ = 833342679000. Its totient is φ = 278370183168.

The previous prime is 491544913789. The next prime is 491544913813. The reversal of 491544913797 is 797319445194.

491544913797 is a `hidden beast` number, since 4 + 9 + 1 + 54 + 491 + 3 + 7 + 97 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 38520342756 + 453024571041 = 196266^2 + 673071^2 .

It is not a de Polignac number, because 491544913797 - 2³ = 491544913789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491544913297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 30020829 + ... + 30037197.

It is an arithmetic number, because the mean of its divisors is an integer number (11574203875).

Almost surely, 2^491544913797 is an apocalyptic number.

It is an amenable number.

491544913797 is a deficient number, since it is larger than the sum of its proper divisors (341797765203).

491544913797 is a wasteful number, since it uses less digits than its factorization.

491544913797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16995 (or 16985 counting only the distinct ones).

The product of its digits is 34292160, while the sum is 63.

The spelling of 491544913797 in words is "four hundred ninety-one billion, five hundred forty-four million, nine hundred thirteen thousand, seven hundred ninety-seven".