723030721 has 6 divisors (see below), whose sum is σ = 841076610. Its totient is φ = 619740576.

The previous prime is 723030709. The next prime is 723030739. The reversal of 723030721 is 127030327.

It can be written as a sum of positive squares in only one way, i.e., 699020721 + 24010000 = 26439^2 + 4900^2 .

It is not a de Polignac number, because 723030721 - 2¹⁵ = 722997953 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (723030421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7377816 + ... + 7377913.

It is an arithmetic number, because the mean of its divisors is an integer number (140179435).

Almost surely, 2^723030721 is an apocalyptic number.

It is an amenable number.

723030721 is a deficient number, since it is larger than the sum of its proper divisors (118045889).

723030721 is a wasteful number, since it uses less digits than its factorization.

723030721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14755743 (or 14755736 counting only the distinct ones).

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

The square root of 723030721 is about 26889.2305765710. The cubic root of 723030721 is about 897.5367710718.

The spelling of 723030721 in words is "seven hundred twenty-three million, thirty thousand, seven hundred twenty-one".