863221 has 4 divisors (see below), whose sum is σ = 866700. Its totient is φ = 859744.

The previous prime is 863197. The next prime is 863231. The reversal of 863221 is 122368.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 239121 + 624100 = 489^2 + 790^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-863221 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 863192 and 863201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (863231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1336 + ... + 1873.

It is an arithmetic number, because the mean of its divisors is an integer number (216675).

2⁸⁶³²²¹ is an apocalyptic number.

It is an amenable number.

863221 is a deficient number, since it is larger than the sum of its proper divisors (3479).

863221 is a wasteful number, since it uses less digits than its factorization.

863221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3478.

The product of its digits is 576, while the sum is 22.

The square root of 863221 is about 929.0968733130. The cubic root of 863221 is about 95.2154298484.

Adding to 863221 its reverse (122368), we get a palindrome (985589).

The spelling of 863221 in words is "eight hundred sixty-three thousand, two hundred twenty-one".