491705640 has 96 divisors (see below), whose sum is σ = 1657262880. Its totient is φ = 131118912.

The previous prime is 491705639. The next prime is 491705651. The reversal of 491705640 is 46507194.

491705640 is a `hidden beast` number, since 4 + 9 + 1 + 7 + 0 + 5 + 640 = 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 = 491705595 and 491705604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15574 + ... + 35013.

It is an arithmetic number, because the mean of its divisors is an integer number (17263155).

Almost surely, 2^491705640 is an apocalyptic number.

491705640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491705640 is an abundant number, since it is smaller than the sum of its proper divisors (1165557240).

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

491705640 is a wasteful number, since it uses less digits than its factorization.

491705640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50613 (or 50597 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 491705640 is about 22174.4366332045. The cubic root of 491705640 is about 789.2872062300.

The spelling of 491705640 in words is "four hundred ninety-one million, seven hundred five thousand, six hundred forty".