820281 has 32 divisors (see below), whose sum is σ = 1410048. Its totient is φ = 411840.

The previous prime is 820279. The next prime is 820319. The reversal of 820281 is 182028.

It is not a de Polignac number, because 820281 - 2¹ = 820279 is a prime.

It is a super-2 number, since 2×820281² = 1345721837922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 7.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820281.

It is not an unprimeable number, because it can be changed into a prime (820201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12210 + ... + 12276.

It is an arithmetic number, because the mean of its divisors is an integer number (44064).

2⁸²⁰²⁸¹ is an apocalyptic number.

It is an amenable number.

820281 is a deficient number, since it is larger than the sum of its proper divisors (589767).

820281 is a wasteful number, since it uses less digits than its factorization.

820281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141.

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 820281 is about 905.6936568178. The cubic root of 820281 is about 93.6097066053.

The spelling of 820281 in words is "eight hundred twenty thousand, two hundred eighty-one".