321913 has 4 divisors (see below), whose sum is σ = 325620. Its totient is φ = 318208.

The previous prime is 321911. The next prime is 321947. The reversal of 321913 is 319123.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 319123 = 7 ⋅45589.

It can be written as a sum of positive squares in 2 ways, for example, as 21609 + 300304 = 147^2 + 548^2 .

It is a cyclic number.

It is not a de Polignac number, because 321913 - 2¹ = 321911 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1720 + ... + 1897.

It is an arithmetic number, because the mean of its divisors is an integer number (81405).

2³²¹⁹¹³ is an apocalyptic number.

It is an amenable number.

321913 is a deficient number, since it is larger than the sum of its proper divisors (3707).

321913 is an equidigital number, since it uses as much as digits as its factorization.

321913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3706.

The product of its digits is 162, while the sum is 19.

The square root of 321913 is about 567.3737745085. The cubic root of 321913 is about 68.5350664935.

It can be divided in two parts, 32 and 1913, that multiplied together give a palindrome (61216).

The spelling of 321913 in words is "three hundred twenty-one thousand, nine hundred thirteen".