720553 has 4 divisors (see below), whose sum is σ = 722260. Its totient is φ = 718848.

The previous prime is 720547. The next prime is 720569. The reversal of 720553 is 355027.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 138384 + 582169 = 372^2 + 763^2 .

It is a cyclic number.

It is not a de Polignac number, because 720553 - 2¹⁷ = 589481 is a prime.

It is a Duffinian number.

720553 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (720053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301 + ... + 1237.

It is an arithmetic number, because the mean of its divisors is an integer number (180565).

2⁷²⁰⁵⁵³ is an apocalyptic number.

It is an amenable number.

720553 is a deficient number, since it is larger than the sum of its proper divisors (1707).

720553 is an equidigital number, since it uses as much as digits as its factorization.

720553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1706.

The product of its (nonzero) digits is 1050, while the sum is 22.

The square root of 720553 is about 848.8539332535. The cubic root of 720553 is about 89.6510355110.

The spelling of 720553 in words is "seven hundred twenty thousand, five hundred fifty-three".