7979488721 has 2 divisors, whose sum is σ = 7979488722. Its totient is φ = 7979488720.

The previous prime is 7979488687. The next prime is 7979488793. The reversal of 7979488721 is 1278849797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5261326225 + 2718162496 = 72535^2 + 52136^2 .

It is an emirp because it is prime and its reverse (1278849797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7979488721 - 2¹⁰ = 7979487697 is a prime.

It is not a weakly prime, because it can be changed into another prime (7979488021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3989744360 + 3989744361.

It is an arithmetic number, because the mean of its divisors is an integer number (3989744361).

Almost surely, 2^7979488721 is an apocalyptic number.

It is an amenable number.

7979488721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7979488721 is an equidigital number, since it uses as much as digits as its factorization.

7979488721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14224896, while the sum is 62.

The square root of 7979488721 is about 89327.9839747881. The cubic root of 7979488721 is about 1998.2892638581.

The spelling of 7979488721 in words is "seven billion, nine hundred seventy-nine million, four hundred eighty-eight thousand, seven hundred twenty-one".