723221 has 2 divisors, whose sum is σ = 723222. Its totient is φ = 723220.

The previous prime is 723209. The next prime is 723227. The reversal of 723221 is 122327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 592900 + 130321 = 770^2 + 361^2 .

It is an emirp because it is prime and its reverse (122327) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 723221 - 2⁶ = 723157 is a prime.

It is a super-2 number, since 2×723221² = 1046097229682, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 723221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (723227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361610 + 361611.

It is an arithmetic number, because the mean of its divisors is an integer number (361611).

2⁷²³²²¹ is an apocalyptic number.

It is an amenable number.

723221 is a deficient number, since it is larger than the sum of its proper divisors (1).

723221 is an equidigital number, since it uses as much as digits as its factorization.

723221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 168, while the sum is 17.

The square root of 723221 is about 850.4240118905. The cubic root of 723221 is about 89.7615498672.

Adding to 723221 its reverse (122327), we get a palindrome (845548).

The spelling of 723221 in words is "seven hundred twenty-three thousand, two hundred twenty-one", and thus it is an iban number.