491521 has 8 divisors (see below), whose sum is σ = 538920. Its totient is φ = 446208.

The previous prime is 491503. The next prime is 491527. The reversal of 491521 is 125194.

It can be written as a sum of positive squares in 4 ways, for example, as 230400 + 261121 = 480^2 + 511^2 .

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

It is a cyclic number.

It is a Cullen number, since it is equal to 15×2¹⁵+1.

It is not a de Polignac number, because 491521 - 2⁵ = 491489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 491492 and 491501.

It is not an unprimeable number, because it can be changed into a prime (491527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6 + ... + 991.

It is an arithmetic number, because the mean of its divisors is an integer number (67365).

It is a Proth number, since it is equal to 15 ⋅ 2¹⁵ + 1 and 15 < 2¹⁵.

2⁴⁹¹⁵²¹ is an apocalyptic number.

It is an amenable number.

491521 is a deficient number, since it is larger than the sum of its proper divisors (47399).

491521 is a wasteful number, since it uses less digits than its factorization.

491521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1043.

The product of its digits is 360, while the sum is 22.

The square root of 491521 is about 701.0855867867. The cubic root of 491521 is about 78.9188398988.

It can be divided in two parts, 49 and 1521, that multiplied together give a square (74529 = 273²).

The spelling of 491521 in words is "four hundred ninety-one thousand, five hundred twenty-one".