491687109144 has 320 divisors, whose sum is σ = 1746114796800. Its totient is φ = 125545593600.

The previous prime is 491687109127. The next prime is 491687109149. The reversal of 491687109144 is 441901786194.

It is a happy number.

491687109144 is a `hidden beast` number, since 491 + 6 + 8 + 7 + 1 + 0 + 9 + 144 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491687109149) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2860354 + ... + 3027374.

It is an arithmetic number, because the mean of its divisors is an integer number (5456608740).

Almost surely, 2^491687109144 is an apocalyptic number.

491687109144 is a gapful number since it is divisible by the number (44) 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 491687109144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (873057398400).

491687109144 is an abundant number, since it is smaller than the sum of its proper divisors (1254427687656).

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

491687109144 is a wasteful number, since it uses less digits than its factorization.

491687109144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167116 (or 167103 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 491687109144 in words is "four hundred ninety-one billion, six hundred eighty-seven million, one hundred nine thousand, one hundred forty-four".