320857 has 4 divisors (see below), whose sum is σ = 322000. Its totient is φ = 319716.

The previous prime is 320851. The next prime is 320861. The reversal of 320857 is 758023.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 758023 = 7 ⋅108289.

It is a cyclic number.

It is not a de Polignac number, because 320857 - 2¹¹ = 318809 is a prime.

It is a d-powerful number, because it can be written as 3¹¹ + 2¹⁵ + 8⁵ + 0 + 5⁷ + 7² .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320851) 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, 178 + ... + 820.

It is an arithmetic number, because the mean of its divisors is an integer number (80500).

2³²⁰⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

320857 is a deficient number, since it is larger than the sum of its proper divisors (1143).

320857 is an equidigital number, since it uses as much as digits as its factorization.

320857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 320857 is about 566.4424066046. The cubic root of 320857 is about 68.4600438300.

The spelling of 320857 in words is "three hundred twenty thousand, eight hundred fifty-seven".