203443921 has 2 divisors, whose sum is σ = 203443922. Its totient is φ = 203443920.

The previous prime is 203443907. The next prime is 203443937. The reversal of 203443921 is 129344302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197093521 + 6350400 = 14039^2 + 2520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-203443921 is a prime.

It is a Chen prime.

It is equal to p_11259091 and since 203443921 and 11259091 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 203443921.

It is not a weakly prime, because it can be changed into another prime (203443951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101721960 + 101721961.

It is an arithmetic number, because the mean of its divisors is an integer number (101721961).

Almost surely, 2^203443921 is an apocalyptic number.

It is an amenable number.

203443921 is a deficient number, since it is larger than the sum of its proper divisors (1).

203443921 is an equidigital number, since it uses as much as digits as its factorization.

203443921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 203443921 is about 14263.3769143215. The cubic root of 203443921 is about 588.1411582446.

The spelling of 203443921 in words is "two hundred three million, four hundred forty-three thousand, nine hundred twenty-one".