79909009 has 4 divisors (see below), whose sum is σ = 81034560. Its totient is φ = 78783460.

The previous prime is 79908989. The next prime is 79909019. The reversal of 79909009 is 90090997.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79909009 - 2⁹ = 79908497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79909019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 562669 + ... + 562810.

It is an arithmetic number, because the mean of its divisors is an integer number (20258640).

Almost surely, 2^79909009 is an apocalyptic number.

It is an amenable number.

79909009 is a deficient number, since it is larger than the sum of its proper divisors (1125551).

79909009 is a wasteful number, since it uses less digits than its factorization.

79909009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125550.

The product of its (nonzero) digits is 45927, while the sum is 43.

The square root of 79909009 is about 8939.1839112975. The cubic root of 79909009 is about 430.7235142263.

The spelling of 79909009 in words is "seventy-nine million, nine hundred nine thousand, nine".