723991 has 8 divisors (see below), whose sum is σ = 752400. Its totient is φ = 696192.

The previous prime is 723977. The next prime is 723997. The reversal of 723991 is 199327.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 723991 - 2⁵ = 723959 is a prime.

It is a d-powerful number, because it can be written as 7⁴ + 2¹⁷ + 9⁵ + 3³ + 9⁶ + 1 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4785 + ... + 4933.

It is an arithmetic number, because the mean of its divisors is an integer number (94050).

2⁷²³⁹⁹¹ is an apocalyptic number.

723991 is a deficient number, since it is larger than the sum of its proper divisors (28409).

723991 is a wasteful number, since it uses less digits than its factorization.

723991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305.

The product of its digits is 3402, while the sum is 31.

The square root of 723991 is about 850.8766068003. The cubic root of 723991 is about 89.7933943881.

The spelling of 723991 in words is "seven hundred twenty-three thousand, nine hundred ninety-one".