9966143021 has 2 divisors, whose sum is σ = 9966143022. Its totient is φ = 9966143020.

The previous prime is 9966142993. The next prime is 9966143039. The reversal of 9966143021 is 1203416699.

9966143021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8020098025 + 1946044996 = 89555^2 + 44114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9966143021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9966143021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9966143051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4983071510 + 4983071511.

It is an arithmetic number, because the mean of its divisors is an integer number (4983071511).

Almost surely, 2^9966143021 is an apocalyptic number.

It is an amenable number.

9966143021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9966143021 is an equidigital number, since it uses as much as digits as its factorization.

9966143021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 9966143021 is about 99830.5715750441. The cubic root of 9966143021 is about 2152.0005191705. Note that the first 3 decimals are identical.

The spelling of 9966143021 in words is "nine billion, nine hundred sixty-six million, one hundred forty-three thousand, twenty-one".