7949966021 has 2 divisors, whose sum is σ = 7949966022. Its totient is φ = 7949966020.

The previous prime is 7949965979. The next prime is 7949966023. The reversal of 7949966021 is 1206699497.

7949966021 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., 4992129025 + 2957836996 = 70655^2 + 54386^2 .

It is a cyclic number.

It is not a de Polignac number, because 7949966021 - 2³⁰ = 6876224197 is a prime.

It is a Sophie Germain prime.

Together with 7949966023, it forms a pair of twin primes.

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 (7949966023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3974983010 + 3974983011.

It is an arithmetic number, because the mean of its divisors is an integer number (3974983011).

Almost surely, 2^7949966021 is an apocalyptic number.

It is an amenable number.

7949966021 is a deficient number, since it is larger than the sum of its proper divisors (1).

7949966021 is an equidigital number, since it uses as much as digits as its factorization.

7949966021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1469664, while the sum is 53.

The square root of 7949966021 is about 89162.5819556612. The cubic root of 7949966021 is about 1995.8217790634.

The spelling of 7949966021 in words is "seven billion, nine hundred forty-nine million, nine hundred sixty-six thousand, twenty-one".