723640 has 32 divisors (see below), whose sum is σ = 1656000. Its totient is φ = 284544.

The previous prime is 723623. The next prime is 723661. The reversal of 723640 is 46327.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3046 + ... + 3274.

It is an arithmetic number, because the mean of its divisors is an integer number (51750).

2⁷²³⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 723640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (828000).

723640 is an abundant number, since it is smaller than the sum of its proper divisors (932360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

723640 is a wasteful number, since it uses less digits than its factorization.

723640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 315 counting only the distinct ones).

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

The square root of 723640 is about 850.6703239211. The cubic root of 723640 is about 89.7788810511.

Adding to 723640 its reverse (46327), we get a palindrome (769967).

The spelling of 723640 in words is "seven hundred twenty-three thousand, six hundred forty".