491890205 has 4 divisors (see below), whose sum is σ = 590268252. Its totient is φ = 393512160.

The previous prime is 491890187. The next prime is 491890211. The reversal of 491890205 is 502098194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 91049764 + 400840441 = 9542^2 + 20021^2 .

It is a de Polignac number, because none of the positive numbers 2^k-491890205 is a prime.

It is a super-4 number, since 4×491890205⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49189016 + ... + 49189025.

It is an arithmetic number, because the mean of its divisors is an integer number (147567063).

Almost surely, 2^491890205 is an apocalyptic number.

It is an amenable number.

491890205 is a deficient number, since it is larger than the sum of its proper divisors (98378047).

491890205 is an equidigital number, since it uses as much as digits as its factorization.

491890205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98378046.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 491890205 is about 22178.5979042860. The cubic root of 491890205 is about 789.3859486201.

The spelling of 491890205 in words is "four hundred ninety-one million, eight hundred ninety thousand, two hundred five".