821993033 has 2 divisors, whose sum is σ = 821993034. Its totient is φ = 821993032.

The previous prime is 821993017. The next prime is 821993047. The reversal of 821993033 is 330399128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 638471824 + 183521209 = 25268^2 + 13547^2 .

It is a cyclic number.

It is not a de Polignac number, because 821993033 - 2⁴ = 821993017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (821993083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410996516 + 410996517.

It is an arithmetic number, because the mean of its divisors is an integer number (410996517).

Almost surely, 2^821993033 is an apocalyptic number.

It is an amenable number.

821993033 is a deficient number, since it is larger than the sum of its proper divisors (1).

821993033 is an equidigital number, since it uses as much as digits as its factorization.

821993033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 821993033 is about 28670.4208723904. The cubic root of 821993033 is about 936.7478655532.

The spelling of 821993033 in words is "eight hundred twenty-one million, nine hundred ninety-three thousand, thirty-three".