723438 has 16 divisors (see below), whose sum is σ = 1607760. Its totient is φ = 241128.

The previous prime is 723421. The next prime is 723439. The reversal of 723438 is 834327.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723439) by changing a digit.

723438 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 7 ways as a sum of consecutive naturals, for example, 6645 + ... + 6752.

It is an arithmetic number, because the mean of its divisors is an integer number (100485).

2⁷²³⁴³⁸ is an apocalyptic number.

723438 is an abundant number, since it is smaller than the sum of its proper divisors (884322).

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

723438 is a wasteful number, since it uses less digits than its factorization.

723438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13408 (or 13402 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 723438 is about 850.5515857372. The cubic root of 723438 is about 89.7705265186.

Subtracting 723438 from its reverse (834327), we obtain a square (110889 = 333²).

The spelling of 723438 in words is "seven hundred twenty-three thousand, four hundred thirty-eight".