491081564160 has 1080 divisors, whose sum is σ = 1989180929736. Its totient is φ = 114944901120.

The previous prime is 491081564143. The next prime is 491081564201. The reversal of 491081564160 is 61465180194.

491081564160 is a `hidden beast` number, since 4 + 9 + 1 + 0 + 81 + 564 + 1 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1080).

It is a super-2 number, since 2×491081564160² (a number of 24 digits) contains 22 as substring.

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 59 ways as a sum of consecutive naturals, for example, 16933847026 + ... + 16933847054.

Almost surely, 2^491081564160 is an apocalyptic number.

491081564160 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 491081564160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (994590464868).

491081564160 is an abundant number, since it is smaller than the sum of its proper divisors (1498099365576).

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

491081564160 is an frugal number, since it uses more digits than its factorization.

491081564160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 491081564160 in words is "four hundred ninety-one billion, eighty-one million, five hundred sixty-four thousand, one hundred sixty".