491761 has 4 divisors (see below), whose sum is σ = 502272. Its totient is φ = 481252.

The previous prime is 491747. The next prime is 491773. The reversal of 491761 is 167194.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 167194 = 2 ⋅83597.

It is a cyclic number.

It is not a de Polignac number, because 491761 - 2⁷ = 491633 is a prime.

It is a super-2 number, since 2×491761² = 483657762242, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491731) 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, 5185 + ... + 5278.

It is an arithmetic number, because the mean of its divisors is an integer number (125568).

2⁴⁹¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

491761 is a deficient number, since it is larger than the sum of its proper divisors (10511).

491761 is a wasteful number, since it uses less digits than its factorization.

491761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510.

The product of its digits is 1512, while the sum is 28.

The square root of 491761 is about 701.2567290230. The cubic root of 491761 is about 78.9316826458.

The spelling of 491761 in words is "four hundred ninety-one thousand, seven hundred sixty-one".