7979996021 has 2 divisors, whose sum is σ = 7979996022. Its totient is φ = 7979996020.

The previous prime is 7979995997. The next prime is 7979996023. The reversal of 7979996021 is 1206999797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4585185796 + 3394810225 = 67714^2 + 58265^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7979996021 is a prime.

Together with 7979996023, 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 (7979996023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3989998010 + 3989998011.

It is an arithmetic number, because the mean of its divisors is an integer number (3989998011).

Almost surely, 2^7979996021 is an apocalyptic number.

It is an amenable number.

7979996021 is a deficient number, since it is larger than the sum of its proper divisors (1).

7979996021 is an equidigital number, since it uses as much as digits as its factorization.

7979996021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3857868, while the sum is 59.

The square root of 7979996021 is about 89330.8234653638. The cubic root of 7979996021 is about 1998.3316103750.

The spelling of 7979996021 in words is "seven billion, nine hundred seventy-nine million, nine hundred ninety-six thousand, twenty-one".