491843861 has 32 divisors (see below), whose sum is σ = 554188800. Its totient is φ = 434600640.

The previous prime is 491843819. The next prime is 491843873. The reversal of 491843861 is 168348194.

It is a cyclic number.

It is not a de Polignac number, because 491843861 - 2¹⁰ = 491842837 is a prime.

It is a super-3 number, since 3×491843861³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491840861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3017366 + ... + 3017528.

It is an arithmetic number, because the mean of its divisors is an integer number (17318400).

Almost surely, 2^491843861 is an apocalyptic number.

It is an amenable number.

491843861 is a deficient number, since it is larger than the sum of its proper divisors (62344939).

491843861 is a wasteful number, since it uses less digits than its factorization.

491843861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369.

The product of its digits is 165888, while the sum is 44.

The square root of 491843861 is about 22177.5530886525. The cubic root of 491843861 is about 789.3611568739.

The spelling of 491843861 in words is "four hundred ninety-one million, eight hundred forty-three thousand, eight hundred sixty-one".