7979821979 has 4 divisors (see below), whose sum is σ = 8014070376. Its totient is φ = 7945573584.

The previous prime is 7979821973. The next prime is 7979822023. The reversal of 7979821979 is 9791289797.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 7979821979 - 2²⁰ = 7978773403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7979821973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17123849 + ... + 17124314.

It is an arithmetic number, because the mean of its divisors is an integer number (2003517594).

Almost surely, 2^7979821979 is an apocalyptic number.

7979821979 is a deficient number, since it is larger than the sum of its proper divisors (34248397).

7979821979 is a wasteful number, since it uses less digits than its factorization.

7979821979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34248396.

The product of its digits is 36006768, while the sum is 68.

The square root of 7979821979 is about 89329.8493170116. The cubic root of 7979821979 is about 1998.3170825416.

The spelling of 7979821979 in words is "seven billion, nine hundred seventy-nine million, eight hundred twenty-one thousand, nine hundred seventy-nine".