818281 has 2 divisors, whose sum is σ = 818282. Its totient is φ = 818280.

The previous prime is 818249. The next prime is 818287. The reversal of 818281 is 182818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 810000 + 8281 = 900^2 + 91^2 .

It is a cyclic number.

It is not a de Polignac number, because 818281 - 2⁵ = 818249 is a prime.

It is a super-2 number, since 2×818281² = 1339167589922, which contains 22 as substring.

It is a Chen prime.

818281 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (818287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409140 + 409141.

It is an arithmetic number, because the mean of its divisors is an integer number (409141).

2⁸¹⁸²⁸¹ is an apocalyptic number.

It is an amenable number.

818281 is a deficient number, since it is larger than the sum of its proper divisors (1).

818281 is an equidigital number, since it uses as much as digits as its factorization.

818281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1024, while the sum is 28.

The square root of 818281 is about 904.5888568847. The cubic root of 818281 is about 93.5335653080.

It can be divided in two parts, 81 and 8281, that multiplied together give a square (670761 = 819²).

The spelling of 818281 in words is "eight hundred eighteen thousand, two hundred eighty-one".