326721 has 4 divisors (see below), whose sum is σ = 435632. Its totient is φ = 217812.

The previous prime is 326707. The next prime is 326737. The reversal of 326721 is 127623.

It is a happy number.

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.

It is not a de Polignac number, because 326721 - 2⁶ = 326657 is a prime.

It is a super-2 number, since 2×326721² = 213493223682, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

326721 is a lucky number.

It is a zygodrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (326701) 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, 54451 + ... + 54456.

It is an arithmetic number, because the mean of its divisors is an integer number (108908).

2³²⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

326721 is a deficient number, since it is larger than the sum of its proper divisors (108911).

326721 is a wasteful number, since it uses less digits than its factorization.

326721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108910.

The product of its digits is 504, while the sum is 21.

The square root of 326721 is about 571.5951364384. The cubic root of 326721 is about 68.8745884102.

The spelling of 326721 in words is "three hundred twenty-six thousand, seven hundred twenty-one".