721743313 has 4 divisors (see below), whose sum is σ = 764198820. Its totient is φ = 679287808.

The previous prime is 721743259. The next prime is 721743331. The reversal of 721743313 is 313347127.

721743313 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 217651009 + 504092304 = 14753^2 + 22452^2 .

It is a cyclic number.

It is not a de Polignac number, because 721743313 - 2²⁵ = 688188881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721743343) 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, 21227728 + ... + 21227761.

It is an arithmetic number, because the mean of its divisors is an integer number (191049705).

Almost surely, 2^721743313 is an apocalyptic number.

It is an amenable number.

721743313 is a deficient number, since it is larger than the sum of its proper divisors (42455507).

721743313 is a wasteful number, since it uses less digits than its factorization.

721743313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42455506.

The product of its digits is 10584, while the sum is 31.

The square root of 721743313 is about 26865.2808099971. The cubic root of 721743313 is about 897.0037450746.

The spelling of 721743313 in words is "seven hundred twenty-one million, seven hundred forty-three thousand, three hundred thirteen".