921009 has 8 divisors (see below), whose sum is σ = 1300320. Its totient is φ = 577856.

The previous prime is 921007. The next prime is 921013. The reversal of 921009 is 900129.

It is a happy number.

921009 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 921009 - 2¹ = 921007 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 921009.

It is not an unprimeable number, because it can be changed into a prime (921001) 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, 8979 + ... + 9080.

It is an arithmetic number, because the mean of its divisors is an integer number (162540).

2⁹²¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

921009 is a deficient number, since it is larger than the sum of its proper divisors (379311).

921009 is a wasteful number, since it uses less digits than its factorization.

921009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18079.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 921009 is about 959.6921381360. The cubic root of 921009 is about 97.2944255054.

The spelling of 921009 in words is "nine hundred twenty-one thousand, nine".