723688221 has 16 divisors (see below), whose sum is σ = 969781248. Its totient is φ = 480034800.

The previous prime is 723688219. The next prime is 723688241. The reversal of 723688221 is 122886327.

723688221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 723688221 - 2¹ = 723688219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 723688221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723688241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 815440 + ... + 816326.

It is an arithmetic number, because the mean of its divisors is an integer number (60611328).

Almost surely, 2^723688221 is an apocalyptic number.

It is an amenable number.

723688221 is a deficient number, since it is larger than the sum of its proper divisors (246093027).

723688221 is a wasteful number, since it uses less digits than its factorization.

723688221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952.

The product of its digits is 64512, while the sum is 39.

The square root of 723688221 is about 26901.4538826436. The cubic root of 723688221 is about 897.8087519704.

The spelling of 723688221 in words is "seven hundred twenty-three million, six hundred eighty-eight thousand, two hundred twenty-one".