9798655021 has 2 divisors, whose sum is σ = 9798655022. Its totient is φ = 9798655020.

The previous prime is 9798654989. The next prime is 9798655033. The reversal of 9798655021 is 1205568979.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5839099396 + 3959555625 = 76414^2 + 62925^2 .

It is an emirp because it is prime and its reverse (1205568979) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9798655021 - 2⁵ = 9798654989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9798655021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9798655051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4899327510 + 4899327511.

It is an arithmetic number, because the mean of its divisors is an integer number (4899327511).

Almost surely, 2^9798655021 is an apocalyptic number.

It is an amenable number.

9798655021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9798655021 is an equidigital number, since it uses as much as digits as its factorization.

9798655021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1360800, while the sum is 52.

The square root of 9798655021 is about 98988.1559632262. The cubic root of 9798655021 is about 2139.8770579647.

The spelling of 9798655021 in words is "nine billion, seven hundred ninety-eight million, six hundred fifty-five thousand, twenty-one".