723040321 has 4 divisors (see below), whose sum is σ = 724248000. Its totient is φ = 721832644.

The previous prime is 723040309. The next prime is 723040343. The reversal of 723040321 is 123040327.

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 a cyclic number.

It is not a de Polignac number, because 723040321 - 2¹³ = 723032129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 723040292 and 723040301.

It is not an unprimeable number, because it can be changed into a prime (723040301) 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, 602941 + ... + 604138.

It is an arithmetic number, because the mean of its divisors is an integer number (181062000).

Almost surely, 2^723040321 is an apocalyptic number.

It is an amenable number.

723040321 is a deficient number, since it is larger than the sum of its proper divisors (1207679).

723040321 is a wasteful number, since it uses less digits than its factorization.

723040321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1207678.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 723040321 is about 26889.4090861067. The cubic root of 723040321 is about 897.5407433856.

Adding to 723040321 its reverse (123040327), we get a palindrome (846080648).

The spelling of 723040321 in words is "seven hundred twenty-three million, forty thousand, three hundred twenty-one".