320729 has 4 divisors (see below), whose sum is σ = 325584. Its totient is φ = 315876.

The previous prime is 320713. The next prime is 320741. The reversal of 320729 is 927023.

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 an emirpimes, since its reverse is a distinct semiprime: 927023 = 53 ⋅17491.

It is a cyclic number.

It is not a de Polignac number, because 320729 - 2⁴ = 320713 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 320729.

It is not an unprimeable number, because it can be changed into a prime (320759) 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, 2327 + ... + 2460.

It is an arithmetic number, because the mean of its divisors is an integer number (81396).

2³²⁰⁷²⁹ is an apocalyptic number.

It is an amenable number.

320729 is a deficient number, since it is larger than the sum of its proper divisors (4855).

320729 is an equidigital number, since it uses as much as digits as its factorization.

320729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4854.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 320729 is about 566.3294094429. The cubic root of 320729 is about 68.4509389940.

The spelling of 320729 in words is "three hundred twenty thousand, seven hundred twenty-nine".