9718021 has 2 divisors, whose sum is σ = 9718022. Its totient is φ = 9718020.

The previous prime is 9718019. The next prime is 9718039. The reversal of 9718021 is 1208179.

9718021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9696996 + 21025 = 3114^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 9718021 - 2¹ = 9718019 is a prime.

Together with 9718019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9718081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4859010 + 4859011.

It is an arithmetic number, because the mean of its divisors is an integer number (4859011).

Almost surely, 2^9718021 is an apocalyptic number.

It is an amenable number.

9718021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9718021 is an equidigital number, since it uses as much as digits as its factorization.

9718021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 9718021 is about 3117.3740551945. The cubic root of 9718021 is about 213.3991135582.

The spelling of 9718021 in words is "nine million, seven hundred eighteen thousand, twenty-one".