623221 has 2 divisors, whose sum is σ = 623222. Its totient is φ = 623220.

The previous prime is 623209. The next prime is 623261. The reversal of 623221 is 122326.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 579121 + 44100 = 761^2 + 210^2 .

It is a cyclic number.

It is not a de Polignac number, because 623221 - 2⁹ = 622709 is a prime.

623221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 623195 and 623204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (623261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311610 + 311611.

It is an arithmetic number, because the mean of its divisors is an integer number (311611).

2⁶²³²²¹ is an apocalyptic number.

It is an amenable number.

623221 is a deficient number, since it is larger than the sum of its proper divisors (1).

623221 is an equidigital number, since it uses as much as digits as its factorization.

623221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 16.

The square root of 623221 is about 789.4434748606. The cubic root of 623221 is about 85.4175989851.

Adding to 623221 its reverse (122326), we get a palindrome (745547).

The spelling of 623221 in words is "six hundred twenty-three thousand, two hundred twenty-one".