718921 has 8 divisors (see below), whose sum is σ = 848384. Its totient is φ = 596160.

The previous prime is 718919. The next prime is 718931. The reversal of 718921 is 129817.

718921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 718921 - 2¹ = 718919 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 718921.

It is not an unprimeable number, because it can be changed into a prime (718901) 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, 1440 + ... + 1873.

It is an arithmetic number, because the mean of its divisors is an integer number (106048).

2⁷¹⁸⁹²¹ is an apocalyptic number.

It is an amenable number.

718921 is a deficient number, since it is larger than the sum of its proper divisors (129463).

718921 is a wasteful number, since it uses less digits than its factorization.

718921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351.

The product of its digits is 1008, while the sum is 28.

The square root of 718921 is about 847.8920921910. The cubic root of 718921 is about 89.5832999940.

The spelling of 718921 in words is "seven hundred eighteen thousand, nine hundred twenty-one".