491605920 has 144 divisors (see below), whose sum is σ = 1806720552. Its totient is φ = 121006080.

The previous prime is 491605913. The next prime is 491605921. The reversal of 491605920 is 29506194.

491605920 is a `hidden beast` number, since 4 + 9 + 1 + 60 + 592 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 138015504 + 353590416 = 11748^2 + 18804^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

It is not an unprimeable number, because it can be changed into a prime (491605921) 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, 5590 + ... + 31850.

Almost surely, 2^491605920 is an apocalyptic number.

491605920 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 491605920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (903360276).

491605920 is an abundant number, since it is smaller than the sum of its proper divisors (1315114632).

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

491605920 is a wasteful number, since it uses less digits than its factorization.

491605920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26295 (or 26284 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 491605920 is about 22172.1879840488. The cubic root of 491605920 is about 789.2338456859.

The spelling of 491605920 in words is "four hundred ninety-one million, six hundred five thousand, nine hundred twenty".