• 723 can be written using four 4's:

723 has 4 divisors (see below), whose sum is σ = 968. Its totient is φ = 480.

The previous prime is 719. The next prime is 727. The reversal of 723 is 327.

723 is nontrivially palindromic in base 15.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 327 = 3 ⋅109.

It is an interprime number because it is at equal distance from previous prime (719) and next prime (727).

It is not a de Polignac number, because 723 - 2^{2} = 719 is a prime.

It is a D-number.

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

It is a Duffinian number.

723 is a lucky number.

723 is a nontrivial repdigit in base 15.

It is a plaindrome in base 14 and base 15.

It is a nialpdrome in base 3, base 9 and base 15.

It is a zygodrome in base 15.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 699 and 708.

It is a congruent number.

It is an inconsummate number, since it does not exist a number *n* which divided by its sum of digits gives 723.

It is not an unprimeable number, because it can be changed into a prime (727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118 + ... + 123.

It is an arithmetic number, because the mean of its divisors is an integer number (242).

2^{723} is an apocalyptic number.

723 is a deficient number, since it is larger than the sum of its proper divisors (245).

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

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

The sum of its prime factors is 244.

The product of its digits is 42, while the sum is 12.

The square root of 723 is about 26.8886593195. Note that the first 3 decimals coincide. The cubic root of 723 is about 8.9752405902.

It can be divided in two parts, 72 and 3, that multiplied together give a cube (216 = 6^{3}).

The spelling of 723 in words is "seven hundred twenty-three", and thus it is an aban number, an iban number, and an oban number.

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