491323521 has 16 divisors (see below), whose sum is σ = 713422080. Its totient is φ = 298953600.

The previous prime is 491323517. The next prime is 491323531. The reversal of 491323521 is 125323194.

It is not a de Polignac number, because 491323521 - 2² = 491323517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491323501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67305 + ... + 74246.

It is an arithmetic number, because the mean of its divisors is an integer number (44588880).

Almost surely, 2^491323521 is an apocalyptic number.

It is an amenable number.

491323521 is a deficient number, since it is larger than the sum of its proper divisors (222098559).

491323521 is a wasteful number, since it uses less digits than its factorization.

491323521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141656.

The product of its digits is 6480, while the sum is 30.

The square root of 491323521 is about 22165.8187532065. The cubic root of 491323521 is about 789.0826937636.

The spelling of 491323521 in words is "four hundred ninety-one million, three hundred twenty-three thousand, five hundred twenty-one".