9980021 has 2 divisors, whose sum is σ = 9980022. Its totient is φ = 9980020.

The previous prime is 9980017. The next prime is 9980029. The reversal of 9980021 is 1200899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7980625 + 1999396 = 2825^2 + 1414^2 .

It is a cyclic number.

It is not a de Polignac number, because 9980021 - 2² = 9980017 is a prime.

It is a Sophie Germain prime.

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 (9980029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990010 + 4990011.

It is an arithmetic number, because the mean of its divisors is an integer number (4990011).

Almost surely, 2^9980021 is an apocalyptic number.

It is an amenable number.

9980021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9980021 is an equidigital number, since it uses as much as digits as its factorization.

9980021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 9980021 is about 3159.1171235014. The cubic root of 9980021 is about 215.2998951764.

The spelling of 9980021 in words is "nine million, nine hundred eighty thousand, twenty-one".