203320021 has 2 divisors, whose sum is σ = 203320022. Its totient is φ = 203320020.

The previous prime is 203320001. The next prime is 203320049. The reversal of 203320021 is 120023302.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166048996 + 37271025 = 12886^2 + 6105^2 .

It is a cyclic number.

It is not a de Polignac number, because 203320021 - 2²¹ = 201222869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 203319983 and 203320010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (203320001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101660010 + 101660011.

It is an arithmetic number, because the mean of its divisors is an integer number (101660011).

Almost surely, 2^203320021 is an apocalyptic number.

It is an amenable number.

203320021 is a deficient number, since it is larger than the sum of its proper divisors (1).

203320021 is an equidigital number, since it uses as much as digits as its factorization.

203320021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 203320021 is about 14259.0329616002. The cubic root of 203320021 is about 588.0217387878.

Adding to 203320021 its reverse (120023302), we get a palindrome (323343323).

The spelling of 203320021 in words is "two hundred three million, three hundred twenty thousand, twenty-one".