491272128 has 168 divisors, whose sum is σ = 1508881920. Its totient is φ = 158319360.

The previous prime is 491272121. The next prime is 491272141. The reversal of 491272128 is 821272194.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 491272092 and 491272101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491272121) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 481603 + ... + 482621.

It is an arithmetic number, because the mean of its divisors is an integer number (8981440).

Almost surely, 2^491272128 is an apocalyptic number.

491272128 is a gapful number since it is divisible by the number (48) 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 491272128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754440960).

491272128 is an abundant number, since it is smaller than the sum of its proper divisors (1017609792).

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

491272128 is a wasteful number, since it uses less digits than its factorization.

491272128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077 (or 1055 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 491272128 is about 22164.6594379431. The cubic root of 491272128 is about 789.0551798214.

The spelling of 491272128 in words is "four hundred ninety-one million, two hundred seventy-two thousand, one hundred twenty-eight".