7899779969 has 2 divisors, whose sum is σ = 7899779970. Its totient is φ = 7899779968.

The previous prime is 7899779957. The next prime is 7899780019. The reversal of 7899779969 is 9699779987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7693570369 + 206209600 = 87713^2 + 14360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7899779969 is a prime.

It is a super-2 number, since 2×7899779969² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7899779893 and 7899779902.

It is not a weakly prime, because it can be changed into another prime (7899779369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3949889984 + 3949889985.

It is an arithmetic number, because the mean of its divisors is an integer number (3949889985).

Almost surely, 2^7899779969 is an apocalyptic number.

It is an amenable number.

7899779969 is a deficient number, since it is larger than the sum of its proper divisors (1).

7899779969 is an equidigital number, since it uses as much as digits as its factorization.

7899779969 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 7899779969 is about 88880.7063934575. The cubic root of 7899779969 is about 1991.6132107927.

The spelling of 7899779969 in words is "seven billion, eight hundred ninety-nine million, seven hundred seventy-nine thousand, nine hundred sixty-nine".