718721 has 4 divisors (see below), whose sum is σ = 721344. Its totient is φ = 716100.

The previous prime is 718717. The next prime is 718723. The reversal of 718721 is 127817.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 718721 - 2² = 718717 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 718721.

It is not an unprimeable number, because it can be changed into a prime (718723) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 845 + ... + 1466.

It is an arithmetic number, because the mean of its divisors is an integer number (180336).

2⁷¹⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

718721 is a deficient number, since it is larger than the sum of its proper divisors (2623).

718721 is a wasteful number, since it uses less digits than its factorization.

718721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2622.

The product of its digits is 784, while the sum is 26.

The square root of 718721 is about 847.7741444512. The cubic root of 718721 is about 89.5749920243.

The spelling of 718721 in words is "seven hundred eighteen thousand, seven hundred twenty-one".