730021 has 2 divisors, whose sum is σ = 730022. Its totient is φ = 730020.

The previous prime is 730003. The next prime is 730033. The reversal of 730021 is 120037.

730021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 617796 + 112225 = 786^2 + 335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-730021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 729983 and 730010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (730091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 365010 + 365011.

It is an arithmetic number, because the mean of its divisors is an integer number (365011).

2⁷³⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

730021 is a deficient number, since it is larger than the sum of its proper divisors (1).

730021 is an equidigital number, since it uses as much as digits as its factorization.

730021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 730021 is about 854.4126637638. The cubic root of 730021 is about 90.0419968608.

Adding to 730021 its reverse (120037), we get a palindrome (850058).

The spelling of 730021 in words is "seven hundred thirty thousand, twenty-one".