491706961920 has 624 divisors, whose sum is σ = 1828986082560. Its totient is φ = 126563254272.

The previous prime is 491706961901. The next prime is 491706961937. The reversal of 491706961920 is 29169607194.

It is a happy number.

491706961920 is a `hidden beast` number, since 4 + 9 + 17 + 0 + 6 + 9 + 619 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 in 47 ways as a sum of consecutive naturals, for example, 144320857 + ... + 144324263.

It is an arithmetic number, because the mean of its divisors is an integer number (2931067440).

Almost surely, 2^491706961920 is an apocalyptic number.

491706961920 is a gapful number since it is divisible by the number (40) 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 491706961920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (914493041280).

491706961920 is an abundant number, since it is smaller than the sum of its proper divisors (1337279120640).

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

491706961920 is an equidigital number, since it uses as much as digits as its factorization.

491706961920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3480 (or 3446 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 491706961920 in words is "four hundred ninety-one billion, seven hundred six million, nine hundred sixty-one thousand, nine hundred twenty".