993443021 has 2 divisors, whose sum is σ = 993443022. Its totient is φ = 993443020.

The previous prime is 993442993. The next prime is 993443023. The reversal of 993443021 is 120344399.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 765130921 + 228312100 = 27661^2 + 15110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-993443021 is a prime.

It is a Sophie Germain prime.

Together with 993443023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993443023) 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, 496721510 + 496721511.

It is an arithmetic number, because the mean of its divisors is an integer number (496721511).

Almost surely, 2^993443021 is an apocalyptic number.

It is an amenable number.

993443021 is a deficient number, since it is larger than the sum of its proper divisors (1).

993443021 is an equidigital number, since it uses as much as digits as its factorization.

993443021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 993443021 is about 31518.9311525629. The cubic root of 993443021 is about 997.8095457468.

The spelling of 993443021 in words is "nine hundred ninety-three million, four hundred forty-three thousand, twenty-one".