723645 has 24 divisors (see below), whose sum is σ = 1351896. Its totient is φ = 355968.

The previous prime is 723623. The next prime is 723661. The reversal of 723645 is 546327.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 47961 + 675684 = 219^2 + 822^2 .

It is not a de Polignac number, because 723645 - 2⁹ = 723133 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34 + ... + 1203.

It is an arithmetic number, because the mean of its divisors is an integer number (56329).

2⁷²³⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

723645 is a deficient number, since it is larger than the sum of its proper divisors (628251).

723645 is a wasteful number, since it uses less digits than its factorization.

723645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261 (or 1258 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 723645 is about 850.6732627748. The cubic root of 723645 is about 89.7790878268.

The spelling of 723645 in words is "seven hundred twenty-three thousand, six hundred forty-five".