281278981 has 2 divisors, whose sum is σ = 281278982. Its totient is φ = 281278980.

The previous prime is 281278979. The next prime is 281279051. The reversal of 281278981 is 189872182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220968225 + 60310756 = 14865^2 + 7766^2 .

It is a cyclic number.

It is not a de Polignac number, because 281278981 - 2¹ = 281278979 is a prime.

It is a super-2 number, since 2×281278981² = 158235730304796722, which contains 22 as substring.

Together with 281278979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281278961) 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 as a sum of consecutive naturals, namely, 140639490 + 140639491.

It is an arithmetic number, because the mean of its divisors is an integer number (140639491).

Almost surely, 2^281278981 is an apocalyptic number.

It is an amenable number.

281278981 is a deficient number, since it is larger than the sum of its proper divisors (1).

281278981 is an equidigital number, since it uses as much as digits as its factorization.

281278981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 46.

The square root of 281278981 is about 16771.3738554717. The cubic root of 281278981 is about 655.2078519886.

The spelling of 281278981 in words is "two hundred eighty-one million, two hundred seventy-eight thousand, nine hundred eighty-one".