491767663968 has 240 divisors, whose sum is σ = 1680904431360. Its totient is φ = 138123304704.

The previous prime is 491767663939. The next prime is 491767663973. The reversal of 491767663968 is 869366767194.

491767663968 is a `hidden beast` number, since 4 + 9 + 176 + 7 + 66 + 396 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 491767663896 and 491767663905.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 840805 + ... + 1300187.

It is an arithmetic number, because the mean of its divisors is an integer number (7003768464).

Almost surely, 2^491767663968 is an apocalyptic number.

491767663968 is a gapful number since it is divisible by the number (48) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491767663968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (840452215680).

491767663968 is an abundant number, since it is smaller than the sum of its proper divisors (1189136767392).

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

491767663968 is a wasteful number, since it uses less digits than its factorization.

491767663968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459471 (or 459454 counting only the distinct ones).

The product of its digits is 493807104, while the sum is 72.

The spelling of 491767663968 in words is "four hundred ninety-one billion, seven hundred sixty-seven million, six hundred sixty-three thousand, nine hundred sixty-eight".