281008381 has 2 divisors, whose sum is σ = 281008382. Its totient is φ = 281008380.

The previous prime is 281008379. The next prime is 281008393. The reversal of 281008381 is 183800182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244296900 + 36711481 = 15630^2 + 6059^2 .

It is a cyclic number.

It is not a de Polignac number, because 281008381 - 2¹ = 281008379 is a prime.

It is a super-2 number, since 2×281008381² = 157931420384482322, which contains 22 as substring.

Together with 281008379, 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 (281008781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140504190 + 140504191.

It is an arithmetic number, because the mean of its divisors is an integer number (140504191).

Almost surely, 2^281008381 is an apocalyptic number.

It is an amenable number.

281008381 is a deficient number, since it is larger than the sum of its proper divisors (1).

281008381 is an equidigital number, since it uses as much as digits as its factorization.

281008381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 281008381 is about 16763.3045966480. The cubic root of 281008381 is about 654.9976737870.

It can be divided in two parts, 28100 and 8381, that added together give a square (36481 = 191²).

The spelling of 281008381 in words is "two hundred eighty-one million, eight thousand, three hundred eighty-one".