913221 has 16 divisors (see below), whose sum is σ = 1368000. Its totient is φ = 602064.

The previous prime is 913217. The next prime is 913247. The reversal of 913221 is 122319.

It is a happy number.

It is not a de Polignac number, because 913221 - 2² = 913217 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 913194 and 913203.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 913221.

It is not an unprimeable number, because it can be changed into a prime (913321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3910 + ... + 4136.

It is an arithmetic number, because the mean of its divisors is an integer number (85500).

2⁹¹³²²¹ is an apocalyptic number.

It is an amenable number.

913221 is a deficient number, since it is larger than the sum of its proper divisors (454779).

913221 is a wasteful number, since it uses less digits than its factorization.

913221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 379 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 913221 is about 955.6259728576. The cubic root of 913221 is about 97.0194101519.

The spelling of 913221 in words is "nine hundred thirteen thousand, two hundred twenty-one".