856321 has 8 divisors (see below), whose sum is σ = 886464. Its totient is φ = 826800.

The previous prime is 856309. The next prime is 856333. The reversal of 856321 is 123658.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (856309) and next prime (856333).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 856321 - 2¹⁵ = 823553 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5596 + ... + 5746.

It is an arithmetic number, because the mean of its divisors is an integer number (110808).

2⁸⁵⁶³²¹ is an apocalyptic number.

It is an amenable number.

856321 is a deficient number, since it is larger than the sum of its proper divisors (30143).

856321 is a wasteful number, since it uses less digits than its factorization.

856321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311.

The product of its digits is 1440, while the sum is 25.

The square root of 856321 is about 925.3761397399. The cubic root of 856321 is about 94.9610551357.

Adding to 856321 its reverse (123658), we get a palindrome (979979).

The spelling of 856321 in words is "eight hundred fifty-six thousand, three hundred twenty-one".