281761 has 2 divisors, whose sum is σ = 281762. Its totient is φ = 281760.

The previous prime is 281747. The next prime is 281767. The reversal of 281761 is 167182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216225 + 65536 = 465^2 + 256^2 .

It is a cyclic number.

It is not a de Polignac number, because 281761 - 2⁹ = 281249 is a prime.

It is a super-2 number, since 2×281761² = 158778522242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140880 + 140881.

It is an arithmetic number, because the mean of its divisors is an integer number (140881).

2²⁸¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

281761 is a deficient number, since it is larger than the sum of its proper divisors (1).

281761 is an equidigital number, since it uses as much as digits as its factorization.

281761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 25.

The square root of 281761 is about 530.8116426756. The cubic root of 281761 is about 65.5581908141.

The spelling of 281761 in words is "two hundred eighty-one thousand, seven hundred sixty-one".