79908989 has 2 divisors, whose sum is σ = 79908990. Its totient is φ = 79908988.

The previous prime is 79908973. The next prime is 79909019. The reversal of 79908989 is 98980997.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72965764 + 6943225 = 8542^2 + 2635^2 .

It is an emirp because it is prime and its reverse (98980997) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79908989 - 2⁴ = 79908973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79908589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39954494 + 39954495.

It is an arithmetic number, because the mean of its divisors is an integer number (39954495).

Almost surely, 2^79908989 is an apocalyptic number.

It is an amenable number.

79908989 is a deficient number, since it is larger than the sum of its proper divisors (1).

79908989 is an equidigital number, since it uses as much as digits as its factorization.

79908989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2939328, while the sum is 59.

The square root of 79908989 is about 8939.1827926271. The cubic root of 79908989 is about 430.7234782918.

The spelling of 79908989 in words is "seventy-nine million, nine hundred eight thousand, nine hundred eighty-nine".