491328540 has 72 divisors (see below), whose sum is σ = 1504889568. Its totient is φ = 129744000.

The previous prime is 491328511. The next prime is 491328547. The reversal of 491328540 is 45823194.

491328540 is a `hidden beast` number, since 4 + 91 + 3 + 28 + 540 = 666.

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 = 491328495 and 491328504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491328547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5290 + ... + 31790.

It is an arithmetic number, because the mean of its divisors is an integer number (20901244).

Almost surely, 2^491328540 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 491328540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (752444784).

491328540 is an abundant number, since it is smaller than the sum of its proper divisors (1013561028).

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

491328540 is a wasteful number, since it uses less digits than its factorization.

491328540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26619 (or 26614 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 491328540 is about 22165.9319677743. The cubic root of 491328540 is about 789.0853806508.

The spelling of 491328540 in words is "four hundred ninety-one million, three hundred twenty-eight thousand, five hundred forty".