491860131840 has 1728 divisors, whose sum is σ = 2301154168320. Its totient is φ = 96825507840.

The previous prime is 491860131817. The next prime is 491860131857. The reversal of 491860131840 is 48131068194.

491860131840 is a `hidden beast` number, since 4 + 9 + 1 + 8 + 601 + 31 + 8 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 25887375351 + ... + 25887375369.

It is an arithmetic number, because the mean of its divisors is an integer number (1331686440).

Almost surely, 2^491860131840 is an apocalyptic number.

491860131840 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 491860131840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150577084160).

491860131840 is an abundant number, since it is smaller than the sum of its proper divisors (1809294036480).

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

491860131840 is an equidigital number, since it uses as much as digits as its factorization.

491860131840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 491860131840 in words is "four hundred ninety-one billion, eight hundred sixty million, one hundred thirty-one thousand, eight hundred forty".