491171688 has 240 divisors, whose sum is σ = 1655280000. Its totient is φ = 135535680.

The previous prime is 491171627. The next prime is 491171713. The reversal of 491171688 is 886171194.

It is a happy number.

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

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, 984063 + ... + 984561.

It is an arithmetic number, because the mean of its divisors is an integer number (6897000).

Almost surely, 2^491171688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491171688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (827640000).

491171688 is an abundant number, since it is smaller than the sum of its proper divisors (1164108312).

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

491171688 is a wasteful number, since it uses less digits than its factorization.

491171688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562 (or 542 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 491171688 is about 22162.3935530439. The cubic root of 491171688 is about 789.0014023598.

It can be divided in two parts, 49117 and 1688, that added together give a palindrome (50805).

The spelling of 491171688 in words is "four hundred ninety-one million, one hundred seventy-one thousand, six hundred eighty-eight".