491221 has 4 divisors (see below), whose sum is σ = 503244. Its totient is φ = 479200.

The previous prime is 491219. The next prime is 491251. The reversal of 491221 is 122194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 255025 + 236196 = 505^2 + 486^2 .

It is a cyclic number.

It is not a de Polignac number, because 491221 - 2¹ = 491219 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491201) 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, 5950 + ... + 6031.

It is an arithmetic number, because the mean of its divisors is an integer number (125811).

2⁴⁹¹²²¹ is an apocalyptic number.

491221 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

491221 is a deficient number, since it is larger than the sum of its proper divisors (12023).

491221 is a wasteful number, since it uses less digits than its factorization.

491221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12022.

The product of its digits is 144, while the sum is 19.

The square root of 491221 is about 700.8716002236. The cubic root of 491221 is about 78.9027805846.

The spelling of 491221 in words is "four hundred ninety-one thousand, two hundred twenty-one".