79877788777889 has 2 divisors, whose sum is σ = 79877788777890. Its totient is φ = 79877788777888.

The previous prime is 79877788777877. The next prime is 79877788777999. The reversal of 79877788777889 is 98877788777897.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71708853099664 + 8168935678225 = 8468108^2 + 2858135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79877788777889 is a prime.

It is a super-2 number, since 2×79877788777889² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (79877788777859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39938894388944 + 39938894388945.

It is an arithmetic number, because the mean of its divisors is an integer number (39938894388945).

Almost surely, 2^{79877788777889} is an apocalyptic number.

It is an amenable number.

79877788777889 is a deficient number, since it is larger than the sum of its proper divisors (1).

79877788777889 is an equidigital number, since it uses as much as digits as its factorization.

79877788777889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2185854418944, while the sum is 107.

The spelling of 79877788777889 in words is "seventy-nine trillion, eight hundred seventy-seven billion, seven hundred eighty-eight million, seven hundred seventy-seven thousand, eight hundred eighty-nine".