305281 has 2 divisors, whose sum is σ = 305282. Its totient is φ = 305280.

The previous prime is 305267. The next prime is 305297. The reversal of 305281 is 182503.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176400 + 128881 = 420^2 + 359^2 .

It is an emirp because it is prime and its reverse (182503) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-305281 is a prime.

It is a super-2 number, since 2×305281² = 186392977922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (305231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152640 + 152641.

It is an arithmetic number, because the mean of its divisors is an integer number (152641).

2³⁰⁵²⁸¹ is an apocalyptic number.

It is an amenable number.

305281 is a deficient number, since it is larger than the sum of its proper divisors (1).

305281 is an equidigital number, since it uses as much as digits as its factorization.

305281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 305281 is about 552.5223977361. The cubic root of 305281 is about 67.3338207548. Note that the first 3 decimals are identical.

Adding to 305281 its reverse (182503), we get a palindrome (487784).

The spelling of 305281 in words is "three hundred five thousand, two hundred eighty-one".