491805405 has 256 divisors, whose sum is σ = 1182720000. Its totient is φ = 192036096.

The previous prime is 491805397. The next prime is 491805409. The reversal of 491805405 is 504508194.

491805405 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 491805405 - 2³ = 491805397 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 491805405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491805409) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 11437314 + ... + 11437356.

It is an arithmetic number, because the mean of its divisors is an integer number (4620000).

Almost surely, 2^491805405 is an apocalyptic number.

491805405 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

491805405 is an abundant number, since it is smaller than the sum of its proper divisors (690914595).

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

491805405 is a wasteful number, since it uses less digits than its factorization.

491805405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 491805405 is about 22176.6860689328. The cubic root of 491805405 is about 789.3405836350.

The spelling of 491805405 in words is "four hundred ninety-one million, eight hundred five thousand, four hundred five".