280688381 has 2 divisors, whose sum is σ = 280688382. Its totient is φ = 280688380.

The previous prime is 280688363. The next prime is 280688417. The reversal of 280688381 is 183886082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 266505625 + 14182756 = 16325^2 + 3766^2 .

It is a cyclic number.

It is not a de Polignac number, because 280688381 - 2²² = 276494077 is a prime.

It is a super-2 number, since 2×280688381² = 157571934456802322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280688341) 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, 140344190 + 140344191.

It is an arithmetic number, because the mean of its divisors is an integer number (140344191).

Almost surely, 2^280688381 is an apocalyptic number.

It is an amenable number.

280688381 is a deficient number, since it is larger than the sum of its proper divisors (1).

280688381 is an equidigital number, since it uses as much as digits as its factorization.

280688381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 147456, while the sum is 44.

The square root of 280688381 is about 16753.7572203969. The cubic root of 280688381 is about 654.7489518259.

The spelling of 280688381 in words is "two hundred eighty million, six hundred eighty-eight thousand, three hundred eighty-one".