79199909 has 2 divisors, whose sum is σ = 79199910. Its totient is φ = 79199908.

The previous prime is 79199903. The next prime is 79199929. The reversal of 79199909 is 90999197.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60684100 + 18515809 = 7790^2 + 4303^2 .

It is an emirp because it is prime and its reverse (90999197) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79199909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79199903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39599954 + 39599955.

It is an arithmetic number, because the mean of its divisors is an integer number (39599955).

Almost surely, 2^79199909 is an apocalyptic number.

It is an amenable number.

79199909 is a deficient number, since it is larger than the sum of its proper divisors (1).

79199909 is an equidigital number, since it uses as much as digits as its factorization.

79199909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 413343, while the sum is 53.

The square root of 79199909 is about 8899.4330718310. The cubic root of 79199909 is about 429.4456693274.

It can be divided in two parts, 79199 and 909, that added together give a palindrome (80108).

The spelling of 79199909 in words is "seventy-nine million, one hundred ninety-nine thousand, nine hundred nine".