9826421021 has 2 divisors, whose sum is σ = 9826421022. Its totient is φ = 9826421020.

The previous prime is 9826420979. The next prime is 9826421023. The reversal of 9826421021 is 1201246289.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9636367225 + 190053796 = 98165^2 + 13786^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9826421021 is a prime.

Together with 9826421023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9826421023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4913210510 + 4913210511.

It is an arithmetic number, because the mean of its divisors is an integer number (4913210511).

Almost surely, 2^9826421021 is an apocalyptic number.

It is an amenable number.

9826421021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9826421021 is an equidigital number, since it uses as much as digits as its factorization.

9826421021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 9826421021 is about 99128.3058515579. The cubic root of 9826421021 is about 2141.8963756889.

The spelling of 9826421021 in words is "nine billion, eight hundred twenty-six million, four hundred twenty-one thousand, twenty-one".