491489720 has 128 divisors (see below), whose sum is σ = 1247400000. Its totient is φ = 173187072.

The previous prime is 491489711. The next prime is 491489741. The reversal of 491489720 is 27984194.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1408106 + ... + 1408454.

Almost surely, 2^491489720 is an apocalyptic number.

491489720 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 491489720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (623700000).

491489720 is an abundant number, since it is smaller than the sum of its proper divisors (755910280).

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

491489720 is a wasteful number, since it uses less digits than its factorization.

491489720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 491489720 is about 22169.5674292486. The cubic root of 491489720 is about 789.1716575281.

The spelling of 491489720 in words is "four hundred ninety-one million, four hundred eighty-nine thousand, seven hundred twenty".