7999779869 has 2 divisors, whose sum is σ = 7999779870. Its totient is φ = 7999779868.

The previous prime is 7999779797. The next prime is 7999779917. The reversal of 7999779869 is 9689779997.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7159359769 + 840420100 = 84613^2 + 28990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7999779869 is a prime.

It is a super-2 number, since 2×7999779869² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 7999779793 and 7999779802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7999179869) 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, 3999889934 + 3999889935.

It is an arithmetic number, because the mean of its divisors is an integer number (3999889935).

Almost surely, 2^7999779869 is an apocalyptic number.

It is an amenable number.

7999779869 is a deficient number, since it is larger than the sum of its proper divisors (1).

7999779869 is an equidigital number, since it uses as much as digits as its factorization.

7999779869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972182736, while the sum is 80.

The square root of 7999779869 is about 89441.4885218264. The cubic root of 7999779869 is about 1999.9816555817.

The spelling of 7999779869 in words is "seven billion, nine hundred ninety-nine million, seven hundred seventy-nine thousand, eight hundred sixty-nine".