821307073 has 2 divisors, whose sum is σ = 821307074. Its totient is φ = 821307072.

The previous prime is 821307049. The next prime is 821307107. The reversal of 821307073 is 370703128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 542517264 + 278789809 = 23292^2 + 16697^2 .

It is a cyclic number.

It is not a de Polignac number, because 821307073 - 2²⁹ = 284436161 is a prime.

It is not a weakly prime, because it can be changed into another prime (821347073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410653536 + 410653537.

It is an arithmetic number, because the mean of its divisors is an integer number (410653537).

Almost surely, 2^821307073 is an apocalyptic number.

It is an amenable number.

821307073 is a deficient number, since it is larger than the sum of its proper divisors (1).

821307073 is an equidigital number, since it uses as much as digits as its factorization.

821307073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 821307073 is about 28658.4555236321. The cubic root of 821307073 is about 936.4872184161.

The spelling of 821307073 in words is "eight hundred twenty-one million, three hundred seven thousand, seventy-three".