1043217821 has 2 divisors, whose sum is σ = 1043217822. Its totient is φ = 1043217820.

The previous prime is 1043217811. The next prime is 1043217863. The reversal of 1043217821 is 1287123401.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 765628900 + 277588921 = 27670^2 + 16661^2 .

It is a cyclic number.

It is not a de Polignac number, because 1043217821 - 2²⁶ = 976108957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1043217811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 521608910 + 521608911.

It is an arithmetic number, because the mean of its divisors is an integer number (521608911).

Almost surely, 2^1043217821 is an apocalyptic number.

It is an amenable number.

1043217821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1043217821 is an equidigital number, since it uses as much as digits as its factorization.

1043217821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 1043217821 is about 32298.8826586927. The cubic root of 1043217821 is about 1014.2032528562.

The spelling of 1043217821 in words is "one billion, forty-three million, two hundred seventeen thousand, eight hundred twenty-one".