730921 has 4 divisors (see below), whose sum is σ = 734292. Its totient is φ = 727552.

The previous prime is 730913. The next prime is 730943. The reversal of 730921 is 129037.

730921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 518400 + 212521 = 720^2 + 461^2 .

It is a cyclic number.

It is not a de Polignac number, because 730921 - 2³ = 730913 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 730892 and 730901.

It is not an unprimeable number, because it can be changed into a prime (730901) 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, 1336 + ... + 1801.

It is an arithmetic number, because the mean of its divisors is an integer number (183573).

2⁷³⁰⁹²¹ is an apocalyptic number.

It is an amenable number.

730921 is a deficient number, since it is larger than the sum of its proper divisors (3371).

730921 is a wasteful number, since it uses less digits than its factorization.

730921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3370.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 730921 is about 854.9391791233. The cubic root of 730921 is about 90.0789841610.

Adding to 730921 its reverse (129037), we get a palindrome (859958).

The spelling of 730921 in words is "seven hundred thirty thousand, nine hundred twenty-one".