720673 has 4 divisors (see below), whose sum is σ = 722500. Its totient is φ = 718848.

The previous prime is 720661. The next prime is 720677. The reversal of 720673 is 376027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 376027 = 23 ⋅16349.

It can be written as a sum of positive squares in 2 ways, for example, as 567009 + 153664 = 753^2 + 392^2 .

It is a cyclic number.

It is not a de Polignac number, because 720673 - 2¹⁷ = 589601 is a prime.

It is a Duffinian number.

720673 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (720677) 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, 48 + ... + 1201.

It is an arithmetic number, because the mean of its divisors is an integer number (180625).

2⁷²⁰⁶⁷³ is an apocalyptic number.

It is an amenable number.

720673 is a deficient number, since it is larger than the sum of its proper divisors (1827).

720673 is a wasteful number, since it uses less digits than its factorization.

720673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826.

The product of its (nonzero) digits is 1764, while the sum is 25.

The square root of 720673 is about 848.9246138498. The cubic root of 720673 is about 89.6560120254.

The spelling of 720673 in words is "seven hundred twenty thousand, six hundred seventy-three".