816281 has 4 divisors (see below), whose sum is σ = 818100. Its totient is φ = 814464.

The previous prime is 816271. The next prime is 816317. The reversal of 816281 is 182618.

816281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 182618 = 2 ⋅91309.

It can be written as a sum of positive squares in 2 ways, for example, as 502681 + 313600 = 709^2 + 560^2 .

It is a cyclic number.

It is not a de Polignac number, because 816281 - 2⁶ = 816217 is a prime.

It is a super-2 number, since 2×816281² = 1332629341922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 816281.

It is not an unprimeable number, because it can be changed into a prime (816251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305 + ... + 1313.

It is an arithmetic number, because the mean of its divisors is an integer number (204525).

2⁸¹⁶²⁸¹ is an apocalyptic number.

It is an amenable number.

816281 is a deficient number, since it is larger than the sum of its proper divisors (1819).

816281 is a wasteful number, since it uses less digits than its factorization.

816281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1818.

The product of its digits is 768, while the sum is 26.

The square root of 816281 is about 903.4827059773. The cubic root of 816281 is about 93.4572998424.

Adding to 816281 its reverse (182618), we get a palindrome (998899).

The spelling of 816281 in words is "eight hundred sixteen thousand, two hundred eighty-one".