308221 has 4 divisors (see below), whose sum is σ = 310012. Its totient is φ = 306432.

The previous prime is 308219. The next prime is 308249. The reversal of 308221 is 122803.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122803 = 37 ⋅3319.

It can be written as a sum of positive squares in 2 ways, for example, as 68121 + 240100 = 261^2 + 490^2 .

It is a cyclic number.

It is not a de Polignac number, because 308221 - 2¹ = 308219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 308195 and 308204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (308291) 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 3 ways as a sum of consecutive naturals, for example, 606 + ... + 991.

It is an arithmetic number, because the mean of its divisors is an integer number (77503).

2³⁰⁸²²¹ is an apocalyptic number.

It is an amenable number.

308221 is a deficient number, since it is larger than the sum of its proper divisors (1791).

308221 is a wasteful number, since it uses less digits than its factorization.

308221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 308221 is about 555.1765484961. The cubic root of 308221 is about 67.5492827107.

It can be divided in two parts, 308 and 221, that added together give a square (529 = 23²).

The spelling of 308221 in words is "three hundred eight thousand, two hundred twenty-one".