491731 has 2 divisors, whose sum is σ = 491732. Its totient is φ = 491730.

The previous prime is 491719. The next prime is 491737. The reversal of 491731 is 137194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491731 - 2⁹ = 491219 is a prime.

It is a super-2 number, since 2×491731² = 483598752722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 491696 and 491705.

It is not a weakly prime, because it can be changed into another prime (491737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245865 + 245866.

It is an arithmetic number, because the mean of its divisors is an integer number (245866).

2⁴⁹¹⁷³¹ is an apocalyptic number.

491731 is the 444-th centered pentagonal number.

491731 is a deficient number, since it is larger than the sum of its proper divisors (1).

491731 is an equidigital number, since it uses as much as digits as its factorization.

491731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 25.

The square root of 491731 is about 701.2353385277. The cubic root of 491731 is about 78.9300775310.

The spelling of 491731 in words is "four hundred ninety-one thousand, seven hundred thirty-one".