491089831 has 4 divisors (see below), whose sum is σ = 491135200. Its totient is φ = 491044464.

The previous prime is 491089777. The next prime is 491089843. The reversal of 491089831 is 138980194.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 138980194 = 2 ⋅69490097.

It is a cyclic number.

It is not a de Polignac number, because 491089831 - 2¹¹ = 491087783 is a prime.

It is a super-2 number, since 2×491089831² = 482338444223217122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491089871) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4075 + ... + 31603.

It is an arithmetic number, because the mean of its divisors is an integer number (122783800).

Almost surely, 2^491089831 is an apocalyptic number.

491089831 is a deficient number, since it is larger than the sum of its proper divisors (45369).

491089831 is a wasteful number, since it uses less digits than its factorization.

491089831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45368.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 491089831 is about 22160.5467215951. The cubic root of 491089831 is about 788.9575691629.

The spelling of 491089831 in words is "four hundred ninety-one million, eighty-nine thousand, eight hundred thirty-one".