79684009 has 2 divisors, whose sum is σ = 79684010. Its totient is φ = 79684008.

The previous prime is 79684001. The next prime is 79684057. The reversal of 79684009 is 90048697.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40896025 + 38787984 = 6395^2 + 6228^2 .

It is a cyclic number.

It is not a de Polignac number, because 79684009 - 2³ = 79684001 is a prime.

It is not a weakly prime, because it can be changed into another prime (79684001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39842004 + 39842005.

It is an arithmetic number, because the mean of its divisors is an integer number (39842005).

Almost surely, 2^79684009 is an apocalyptic number.

It is an amenable number.

79684009 is a deficient number, since it is larger than the sum of its proper divisors (1).

79684009 is an equidigital number, since it uses as much as digits as its factorization.

79684009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 79684009 is about 8926.5899984261. The cubic root of 79684009 is about 430.3188711050.

The spelling of 79684009 in words is "seventy-nine million, six hundred eighty-four thousand, nine".