491173261 has 8 divisors (see below), whose sum is σ = 521844120. Its totient is φ = 461418048.

The previous prime is 491173259. The next prime is 491173297. The reversal of 491173261 is 162371194.

It can be written as a sum of positive squares in 4 ways, for example, as 319301161 + 171872100 = 17869^2 + 13110^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491173261 - 2¹ = 491173259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491153261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 227806 + ... + 229951.

It is an arithmetic number, because the mean of its divisors is an integer number (65230515).

Almost surely, 2^491173261 is an apocalyptic number.

It is an amenable number.

491173261 is a deficient number, since it is larger than the sum of its proper divisors (30670859).

491173261 is a wasteful number, since it uses less digits than its factorization.

491173261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457823.

The product of its digits is 9072, while the sum is 34.

The square root of 491173261 is about 22162.4290410596. The cubic root of 491173261 is about 789.0022446301.

The spelling of 491173261 in words is "four hundred ninety-one million, one hundred seventy-three thousand, two hundred sixty-one".